He held that every fermentation consisted of molecular motion which is transmitted from a substance in a state of chemical motion - that is, of decomposition - to other substances, the elements of which are loosely held together.
This investigator held that the decomposition of the sugar molecules takes place outside the cell wall.
From the foregoing it will be seen that the term fermentation has now a much wider significance than when it was applied to such changes as the decomposition of must or wort with the production of carbon dioxide and alcohol.
It forms white plates, melting at 132°, readily soluble in water, and subliming without decomposition.
It is a liquid which boils at about 165° C. (with partial decomposition); it may be solidified, and when pure melts at 13.6° C. (L.
Conh 2j is a liquid readily soluble in water,, boiling at about 195° C. with partial decomposition.
It is a white crystalline solid of melting point 43° C.; it boils at 210° C., and it can be distilled without decomposition.
Witt), and by the decomposition of ortho-anilido-(-toluidido- &c.)-azo compounds with dilute acids.
It gives rise to various decomposition products such as pyridine, picoline, &c., when its vapour is passed through a red-hot tube.
Davy on the decomposition of the solutions of salts by the voltaic current were turned to account in the water voltameter telegraph of Sdmmering and the modification of it proposed by Schweigger, and in a similar method proposed by Coxe, in which a solution of salts was substituted for water.
Chlorophyll is not soluble in water, nor in acids or alkalies without decomposition.
Brown and Morris in 1892 advanced strong reasons for thinking that cane-sugar, Ci2H22O11, is the first carbohydrate synthesized, and that the hexoses found in the plant result from the decomposition of this.
The digestion of fat or oil has not been adequately investigated, but its decomposition in germinating seeds has been found to be due to an enzyme, which has been called lipase.
This is the absorption of elaborated compounds from their environment, by whose decomposition the potential energy expended in their construction can be liberated.
The material and the energy go together, the decomposition of the one in the cell setting free the other, which is used at once in the vital processes of the cell, being in fact largely employed in constructing protoplasm or storing various products.
This comes in almost all such cases from the decomposition of sugar, which is split up by the protoplasm into alcohol and carbon dioxide.
The decomposition of the complex molecule of the sugar liberates a certain amount of energy, as can be seen from the study of the fermentation set tig by yeast, which is a process of this kind, in that it is intensified by the absence of oxygen.
It has been ascertained that in many cases this decomposition is effected by the secretion of an enzyme, which has been termed zymase.
The formation of living substance is a process of building up from simple or relatively simple materials; the construction of its cellulose framework and supporting substance is done by the living substance after its own formation is completed, and is attended by a partial decomposition of such living substance.
This is evident from the consideration that the growth of the cells is attended by the growth in surface of the cell wall, and as the latter is a secretion from the protoplasm, such a decomposition cannot readily take place unless oxygen is admitted to it.
For instance, a Fungus epidemic is impossible unless the climatic conditions are such as to favor the dispersal and germination of the spores; and when plants are killed off owi~ig to the supersaturation of the soil with water, it is by no means obvious whether the excess of water and dissolved materials, or the exclusion of oxygen from the root-hairs, or the lowering of the temperature, or the accumulation of foul products of decomposition should be put into the foreground.
It is probable that most, if not all, the metabolic changes which take place in a cell, such as the transformation of starch, proteids, sugar, cellulose; and the decomposition -of numerous other organic substances which would otherwise require a high temperature or powerful reagents is also due to their activity.
When phenol is passed through a red-hot tube a complex decomposition takes place, resulting in the formation of benzene, toluene, naphthalene, &c. (J.
Deposits of sulphur are frequently formed by the decomposition of hydrogen sulphide, on exposure to the atmosphere: hence natural sulphureous waters, especially hot springs, readily deposit sulphur.
Free sulphur may also result from the decomposition of pyrites, as in pyritic shales and lignites, or from the alteration of galena: thus crystals of sulphur occur, with anglesite, in cavities in galena at Monteponi near Iglesias in Sardinia; whilst the pyrites of Rio Tinto in Spain sometimes yield sulphur on weathering.
Sulphur bromide, S 2 Br 2, is a dark red liquid which boils with decomposition at about 200° C. The products obtained by the action of iodine on sulphur are probably mixtures, although E.
A solution of the free acid may be obtained by decomposing the barium salt with dilute sulphuric acid and concentrating the solution in vacuo until it attains a density of about 1.35 (approximately), further concentration leading to its decomposition into sulphur dioxide and sulphuric acid.
its heat of decomposition into its elements.
Some of these pass into their elements with explosive violence, owing to the heat generated by their decomposition and the gaseous nature of the products.
Throughout much of the Piedmont Plateau and Mountain regions the decomposition of felspar and of other aluminous minerals has resulted in a deep soil of clay with which more or less sand is mixed.
of mercury it boils at 170° C. In an atmosphere of steam it distils without decomposition under ordinary barometric pressure.
The simplest modes of preparing pure glycerin are based on the saponification of fats, either by alkalis or by superheated steam, and on the circumstance that, although glycerin cannot be distilled by itself under the ordinary pressure without decomposition, it can be readily volatilized in a current of superheated steam.
In the presence of a dehydrating agent (such as acetic anhydride), it combines with aldehydes to form compounds of the type R CH: C(COOH) 2, or their decomposition products (formed by loss of C02) R CH: CH COOH.
part of the state, the soil is largely a decomposition of the underlying rocks, and its fertility varies according to their composition; there is considerable limestone in the E.
The theories propounded may be divided into two groups, namely, those ascribing to petroleum an inorganic origin, and those which regard it as the result of the decomposition of organic matter.
Among those who have considered that it is derived from the decomposition of both animal and vegetable marine organisms may be mentioned J.
This view is supported by the fact that petroleum is found on the Sardinian and Swedish coasts as a product of the decomposition of seaweed, heated only by the sun, and under atmospheric pressure.
Consideration of the evidence leads us to the conclusion that, at least in commercially valuable deposits, mineral oil has generally been formed by the decomposition of marine organisms, in some cases animal, in others vegetable, in others both, under practically normal conditions of temperature and pressure.
The rationale of this treatment is not fully understood, but the action appears to consist in the separation or decomposition of the aromatic hydrocarbons, fatty and other acids, phenols, tarry bodies, &c., which lower the quality of the oil, the sulphuric acid removing some, while the caustic soda takes out the remainder, and neutralizes the acid which has been left in the oil.
The corresponding decomposition of a glyceride into an acid and glycerin takes place when the glyceride is distilled in superheated steam, or by boiling in water mixed with a suitable proportion of caustic potash or soda.
Potash soap with the same reagent undergoes double decomposition - a proportion being changed into a soda soap with the formation of potassium chloride.
There is no separation of underlyes in potash soap, consequently the product contains the whole constituents of the oils used, as the operation of salting out is quite impracticable owing to the double decomposition which results from the action of salt, producing thereby a hard principally soda soap with formation of potassium chloride.
His earlier work was mainly concerned with organic chemistry, and he published researches on picoline and its derivatives in 1876-78 and on quinine and its decomposition products in 1878-79.
It forms silky crystals which melt at 6° C., and boil at about 144° C. with decomposition.
At the same time he clarified the conception of elements and compounds, rejecting the older notions, the four elements of the " vulgar Peripateticks " and the three principles of the " vulgar Stagyrists," and defining an element as a substance incapable of decomposition, and a compound as composed of two or more elements.
One other instance may be given; the equation 2NH3=N2+3H2 represents the decomposition of ammonia gas into nitrogen and hydrogen gases by the electric spark, and it not only conveys the information that a certain relative weight of ammonia, consisting of certain relative weights of hydrogen and nitrogen, is broken up into certain relative weights of hydrogen and nitrogen, but also that the nitrogen will be contained in half the space which contained the ammonia, and that the volume of the hydrogen will be one and a half times as great as that of the original ammonia, so that in the decomposition of ammonia the volume becomes doubled.
changes which involve combination, changes which involve decomposition or separation, and changes which involve at the same time both decomposition and combination.
they appear to differ in character; but if they are correctly represented by molecular equations, or equations which express the relative number of molecules which enter into reaction and which result from the reaction, it will be obvious that the character of the reaction is substantially the same in both cases, and that both are instances of the occurrence of what is ordinarily termed double decomposition H2 + C12 = 2HC1 Hydrogen.
Lastly, in the production of gaseous hydriodic acid from hydrogen and solid iodine H2 - 1 - 12=HI+HI, so much energy is expended in the decomposition of the hydrogen and iodine molecules and in the conversion of the iodine into the gaseous condition, that the heat which it may be supposed is developed by the combination of the hydrogen and iodine atoms is insufficient to balance the expenditure, and the final result is therefore negative; hence it is necessary in forming hydriodic acid from its elements to apply heat continuously.
As another instance of this kind, the decomposition of bismuth chloride by water may be cited.
Chemical change which merely involves simple decomposition is thus seen to be influenced by the masses of the reacting substances and the presence of the products of decomposition; in other words the system of reacting substances and resultants form a mixture in which chemical action has apparently ceased, or the system is in equilibrium.
Certain compounds withstand ring decomposition much more strongly than others; for instance,.
Zincke; and his researches have led to the discovery of many chlorinated oxidation products which admit of decomposition into cyclic compounds containing fewer carbon atoms than characterize the benzene ring, and in turn yielding openchain or aliphatic compounds.
Hantzsch (Ber., 1889, 22, p. 1238) succeeded in ob R taining derivatives of o-diketo-R-hexene, which yield R-pentene and aliphatic compounds on decomposition.
The prism formula also received support from the following data: protocatechuic acid when oxidized by nitrous acid gives carboxytartronic acid, which, on account of its ready decomposition into carbon dioxide and tartronic acid, was considered to be HO C(COOH) 3.
Oxygen, recognized by its power of igniting a glowing splinter, results from the decomposition of oxides of the noble metals, peroxides, chlorates, nitrates and other highly oxygenized salts.
Nitrogen oxides, recognized by their odour and brown-red colour, result from the decomposition of nitrates.
In the case of separation from solutions, either by crystallization or by precipitation by double decomposition, the temperature, the concentration of the solution, and the presence of other ions may modify the form obtained.
It was discovered in 1838 by Piria as a decomposition product of salicin.
It crystallizes in needles and melts at 132° C. (with decomposition).
The addition of a little of the acid to glue renders it more tenacious; skins to be used for making leather do not undergo decomposition if steeped in a dilute solution; butter containing a small quantity of it may be kept sweet for months even in the hottest weather.
Sodium salicylate circulates in the blood unchanged, decomposition occurring in the kidney, and probably in tissues suffering from the Diplococcus rheumaticus of Poynton and Paine.
When the body was exhibited to the people the next day it was in a shocking state of decomposition, which of course strengthened the suspicion of poison.
He also investigated the diamagnetic and paramagnetic properties of substances; and was keenly interested in the phenomena of electrochemical decomposition, accumulating much evidence in favour of Faraday's law and proposing a modified statement of it which was intended to cover certain apparent exceptions.
But the Peckhams' careful observations and experiments show that, with the American wasps, the victims stored in the nests are quite as often dead as alive; that those which are only paralysed live for a varying number of days, some more, some less; that wasp larvae thrive just as well on dead victims, sometimes dried up, sometimes undergoing decomposition, as on living and paralysed prey; that the nerve-centres are not stung with the supposed uniformity; and that in some cases paralysis, in others death, follows when the victims are stung in parts far removed from any nerve-centre.
They are either colourless liquids, which boil without decomposition, or crystalline solids; and are both basic and acidic in character.
Nitrogen peroxide is also prepared by heating lead nitrate and passing the products of decomposition through a tube surrounded by a freezing mixture, when the gas liquefies.
It crystallizes in large prisms which melt at 29-30° C. to a yellowish liquid, which boils at 45-50° C. with rapid decomposition.
Animals cannot make use of these decomposition products, but the plants can.
The general trend of these researches lies in the study of the decomposition or " breaking down " products of the albumin molecules; once these are accurately determined, the synthesis of an albumin is but a matter of time.
Already we have proceeded far in our knowledge of the decomposition products, and certain simple proteids have been synthesized.
These decomposition products include: glycocoll or aminoacetic acid, NH 2 CH 2 Oooh, alanine d ucts.
By further decomposition peptones yield peptides, a certain number of which have been synthesized by Emil Fischer and his collaborators.
The decomposition products are generally the same as with the general albumin; it gives the biuret reaction; forms salts with acids and alkalies, but is essentially acid in nature.
The volume of the hydrogen was about double that of the oxygen, and, since this is the ratio in which these elements are combined in water, it was concluded that the process con sisted essentially in the decomposition of water.
This observation showed that nascent hydrogen was not, as had been supposed, the primary cause of the separation of metals from their solutions, but that the action consisted in a direct decomposition into metal and acid.
He had shown previously that decomposition of water could be effected although the two poles were placed in separate vessels connected by moistened threads.
Acting on this view, Faraday set himself to examine the relation between the flow of electricity round the circuit and the amount of chemical decomposition.
A study of the products of decomposition does not necessarily lead directly to a knowledge of the ions actually employed in carrying the current through the electrolyte.
In aqueous solutions, for instance, a few hydrogen (H) and hydroxyl (OH) ions derived from the water are always present, and will be liberated if the other ions require a higher decomposition voltage and the current be kept so small that hydrogen and hydroxyl ions can be formed fast enough to carry all the current across the junction between solution and electrode.
At the electrodes, however, the small quantity of hydrogen and hydroxyl ions from the water are liberated first in cases where the ions of the salt have a higher decomposition voltage.
The obvious phenomena to be explained by any theory of electrolysis are the liberation of the products of chemical decomposition at the two electrodes while the intervening liquid is unaltered.
If two solutions containing the salts AB and CD be mixed, double decomposition is found to occur, the salts AD and CB being formed till a certain part of the first pair of substances is transformed into an equivalent amount of the second pair.
The tests for a salt, potassium nitrate, for example, are the tests not for KNO 3, but for its ions K and NO 3, and in cases of double decomposition it is always these ions that are exchanged for those of other substances.
If an aqueous solution of methyl acetate be allowed to stand, a slow decomposition goes on.
If we connect together in series a single Daniell's cell, a galvanometer, and two platinum electrodes dipping into acidulated water, no visible chemical decomposition ensues.
This current is accompanied by chemical decomposition.
Only when the applied electromotive force exceeds this reverse force of polarization, will a permanent steady current pass through the liquid, and visible chemical decomposition proceed.
It seems that this reverse electromotive force of polarization is due to the deposit on the electrodes of minute quantities of the products of chemical decomposition.
If the plates be covered with a deposit of platinum black, in which the gases are absorbed as fast as they are produced, the minimum decomposition point is 1.07 volt, and the process is reversible.
If secondary effects are eliminated, the deposition of metals also is a reversible process; the decomposition voltage is equal to the electromotive force which the metal itself gives when going into solution.
In order to prevent decomposition of any proteid impurity which may remain incorporated with the rubber, the freshly coagulated rubber is sometimes cured in the smoke of burning wood or a small quantity of an antiseptic such as creosote is added during coagulation.
At higher temperatures the viscous liquid suffers decomposition with the formation of various liquid hydrocarbons, principally members of the terpene series.
As the carbon content of the molecule increases, they become less soluble in water, and their smell becomes less marked with the increase in boiling point, the highest members of the series being odourless solids, which can only be distilled without decomposition invacuo.
In France, by the 10th century, the process of decomposition of the old organization had gone far, and in the 11th century titles of nobility were still very loosely applied.
The nitro compounds are colourless, somewhat pleasant smelling liquids, which distil without decomposition and possess boiling points much higher than those of the isomeric nitrous esters.
Nitroethane, C2H5N02, is a colourless liquid which boils at 114° C. Nitroform (trinitromethane), CH(N03)3, is obtained in the form of its ammonium salt by the decomposition of trinitroacetonitrile with water (L.
The mono-nitro compounds are stable and distil without decomposition; they have a pale yellow colour and possess an agreeable odour.
A process of waste resulting from the decomposition of the molecules of the protoplasm, in virtue of which they break up into more highly oxidated products, which cease to form any part of the living body, is a constant concomitant of life.
Precipitated stannous hydrate dissolves readily in caustic potash; if the solution is evaporated quickly it suffers decomposition, with formation of metal and stannate, 2SnO+2KOH = K2Sn03+Sn+H20.
It is a white solid, fusing at 250° C. to an oily liquid which boils at 606°, and volatilizing at a red heat in nitrogen, a vacuum or hydrochloric acid, without decomposition.
The idea is that any traces of acid not washed away by the washing process or produced later by a slow decomposition of the substance will be thereby neutralized and rendered harmless.
Another heat test, that of Will, consists in heating a weighed quantity of the guncotton in a stream of carbon dioxide to 130° C., passing the evolved gases over some red-hot copper, and finally collecting them over a solution of potassium hydroxide which retains the carbon dioxide and allows the nitrogen, arising from the guncotton decomposition, to be measured.
This is done at definite time intervals so that the rate of decomposition can be followed.
When the solution in the strong acid is allowed to stand, some nitric acid is first evolved, and as the temperature rises this is followed by a general decomposition of the substance, though not necessarily an explosive one.
Ammonium hydroxide has no appreciable action at ordinary temperatures, but strong solutions of sodium or potassium hydroxides start a decomposition, with rise of temperature, in which some nitrate and always some nitrite is produced.
Nitroglycerin shaken up with warm very dilute alkaline solutions, as sodium carbonate, for a few minutes only, always yields sufficient nitrite to give the diazoreaction; and, as stated, strong alkaline solutions always produce some nitrite as one of the decomposition products.
The outcrop of a metalliferous vein frequently manifests itself as a line of rocks stained with oxide of iron, often honeycombed and porous, the " gossan " or " eisen-hut," the iron oxide of which results from the decomposition of the pyrites, usually present as a constituent of such veins.
The cornmercial product (which is known in Germany as "Kalkstickstof") contains from 14 to 22% of nitrogen, which is liberated as ammonia when the substance is treated with water; to this decomposition it owes its agricultural value.
These bubbles arise partly from the air enclosed between the particles of raw materials and partly from the gaseous decomposition products of the materials themselves.
The older methods used for the preparation of the amorphous form, namely the decomposition of silicon halides or silicofluorides by the alkali metals, or of silica by magnesium, do not give good results, since' the silicon obtained is always contaminated with various impurities, but a pure variety may be prepared according to E.
When pure, it is a colourless gas which is not spontaneously inflammable at ordinary temperature and pressure, but a slight increase of temperature or decrease of pressure sets up decomposition.
These are passed through a vessel surrounded by a freezing mixture and on fractionating the product the hydride distils over as a colourless liquid which boils at 52° C. It is also obtained by the decomposition of lithium silicide with concentrated hydrochloric acid.
It is a colourless, strongly refracting liquid, which boils at about 220° C., slight decomposition setting in above 150° C. Water decomposes it with production of leucone.
The alkaline carbonates undergo only a very slight decomposition, even at a very bright red heat.
The chlorides MgC1 21 A1C13, CrC1 3, FeC1 3, suffer a similar decomposition when evaporated with water in the heat.
It forms hard white rhombic prisms (with 1H 2 0), which become anhydrous at 400 and melt with decomposition at 205°.
Maltose, malt-sugar, maltobiose, C12H22011, is formed, together with dextrine, by the action of malt diastase on starch, and as an intermediate product in the decomposition of starch by sulphuric acid, and of glycogen by ferments.
in diameter) of sand and other minerals derived from the decomposition of rocks, with a small amount of silicate of alumina.
Lime also assists in the decomposition of the organic matter or humus in the soil and promotes nitrification; hence it is of great value after green manuring or where the land contains much humus from the addition of bulky manures such as farm-yard dung.
The results of many analyses show that the capacity of soils for moisture increases with the amount of organic substances present; decomposition appears to be most active when the moisture is about 4%, but can continue when it is as low as 2%, while it appears to be retarded by any excess over 4%.
A solution of zinc chloride is easily produced from the metal and hydrochloric acid; it cannot be evaporated to dryness without considerable decomposition of the hydrated salt into oxychloride and hydrochloric acid, but it may be crystallized as ZnC1 2 H 2 O.
To this end he examined such immediate vital products as blood, bile and urine; he analysed the juices of flesh, establishing the composition of creatin and investigating its decomposition products, creatinin and sarcosin; he classified the various articles of food in accordance with the special function performed by each in the animal economy, and expounded the philosophy of cooking; and in opposition to many of the medical opinions of his time taught that the heat of the body is the result of the processes of combustion and oxidation performed within the organism.
While the population of Nejef is estimated at from 20,000 to 30,000, there is in addition a very large floating population of pilgrims, who are constantly arriving, bringing corpses in all stages of decomposition and accompanied at times by sick and aged persons, who have come to Nejef to die.
This followed from a study of the decomposition products, there being obtained hemipinic acid (CH 3 0) 2 C 6 H 2 (000H) 2, and a substance which proved to be co - amino - ethyl - piperonyl carboxylic acid, CH 2 O 2 :C 6 H 2 [[Cooh-Ch 2 Ch 2 Nh]] 2.
It is also a decomposition product of many alkaloids.
Aromatic Amines.-The aromatic amines in some respects resemble the aliphatic amines, since they form salts with acids, and double salts with platinum chloride, and they also distil without decomposition.
They crystallize in plates, and for the most part distil without decomposition.
For efficiency the operation must be conducted with small quantities; caking may be prevented by mixing the substance with sand or powdered pumice, or, better, with iron filings, which also renders the decomposition more regular by increasing the conductivity of the mass.
Potassium permanganate in acid solution oxidizes it to carbon dioxide and water; the manganese sulphate formed has a catalytic accelerating effect on the decomposition.
It is a crystalline powder difficultly soluble in water and melting at 210° C. (with decomposition).
It melts at 417-419° C. (with decomposition) when heated in a sealed tube (A.
It crystallizes in plates which melt at 220-221° C. (with decomposition).
The intermediate summits occurring in the freezing-point curves of alloys are usually rounded; this feature is believed to be due to the partial decomposition of the compound which takes place when it melts.
It begins to decompose into gold and chlorine at 185°, the decomposition being complete at 230°; water decomposes it into gold and auric chloride.
Pliny shows that for this purpose the gold was placed on the fire in an earthen vessel with treble its weight of salt, and that it was afterwards again exposed to the fire with two parts of salt and one of argillaceous rock, which, in the presence of moisture, effected the decomposition of the salt; by this means the silver became converted into chloride.
It owes its value to the decomposition described above, by means of which a powerful antiseptic action is safely and continuously exerted.
Its advantages rest on its high density and mobility; its main disadvantages are its liability to decomposition, the originally colourless liquid becoming dark owing to the separation of iodine, and its high coefficient of expansion.
rend., 1905, p. 141) has investigated the solutions of mercuric iodide in other alkaline iodides; sodium iodo-mercurate solution has a density of 3.46 at 26°, and gives with an excess of water a dense precipitate of mercuric iodide, which dissolves without decomposition in alcohol; lithium iodo-mercurate solution has a density of 3.28 at 25.6°; and ammonium iodo-mercurate solution a density of 2.98 at 26°.
Sir John Murray finds the source of the phosphoric acid to be the decomposition of large quantities of animal matter, and he illustrates this by the well-known circumstance of the death of vast shoals of fish when warm Gulf-Stream water displaces the cold current which usually extends to the American coast.
As well as the finest of terrigenous clay there is present in sea-water far from land a different clay derived from the decomposition of volcanic material.
It is, however, a curious question how, considering the increase of carbonic acid by the decomposition of organic bodies and possible submarine exhalations of volcanic origin, the water has not in some places become saturated and a precipitate of amorphous calcium carbonate formed in the deepest water.
Caesium hydroxide, Cs(OH) 2, obtained by the decomposition of the sulphate with baryta water,is a greyish-white deliquescent solid,which melts at a red heat and absorbs carbon dioxide rapidly.
Continuing these experiments, they found that in acetylene gas under ordinary pressures the decomposition brought about in one portion of the gas, either by heat or the firing in it of a small detonator, did not spread far beyond the point at which the decomposition started, while if the acetylene was compressed to a pressure of more than 30 lb on the square inch, the decomposition travelled throughout the mass and became in reality detonation.
It has since been shown, however, that unless the gas is at a pressure of more than two atmospheres this wave soon dies out, and the decomposition is only propagated a few inches from the detonator.
Before the commercial production of calcium carbide made it one of the most easily obtainable gases, the processes which were most largely adopted for its preparation in laboratories were: - first, the decomposition of ethylene bromide by dropping it slowly into a boiling solution of alcoholic potash, and purifying the evolved gas from the volatile bromethylene by washing it through a second flask containing a boiling solution of alcoholic potash, or by passing it over moderately heated soda lime; and, second, the more ordinarily adopted process of passing the products of incomplete combustion from a Bunsen burner, the flame of which had struck back, through an ammoniacal solution of cuprous chloride, when the red copper acetylide was produced.
The purity of the carbide entirely depends on the purity of the material used in its manufacture, and before this fact had been fully grasped by manufacturers, and only the purest material obtainable employed, it contained notable quantities of compounds which during its decomposition by water yielded a somewhat high pro portion of impurities in the acetylene generated from it.
On decomposition by water, ammonia is produced by the action of steam or of nascent hydrogen on the nitride, the quantity formed depending very largely upon the temperature at which the carbide is decomposed.
Sulphuretted hydrogen, which is invariably present in commercial acetylene, is formed by the decomposition of aluminium sulphide.
Mourlot has shown that aluminium sulphide, zinc sulphide and cadmium sulphide are the only sulphur compounds which can resist the heat of the electric furnace without decomposition or volatilization, and of these aluminium sulphide is the only one which is decomposed by water with the evolution of sulphuretted hydrogen.
The decomposition of the carbide by water may be brought about either by bringing the water slowly into contact with an excess of carbide, or by dropping the carbide into an excess of water, and these two main operations again may be varied by innumerable ingenious devices by which the rapidity of the contact may be modified or even eventually stopped.
The result is that although the forms of apparatus utilized for this purpose are all based on the one fundamental principle of bringing about the contact of the carbide with the water which is to enter into double decomposition with it, they have been multiplied in number to a very large extent by the methods employed in order to ensure control in working, and to get away from the dangers and inconveniences which are inseparable from a too rapid generation.
Complete decomposition of the carbide.
became so heated as to cause the decomposition of some of the gas before combustion, the jet being choked up by the carbon which deposited in a very dense form; and as the use of acetylene under pressures greater than one hundred inches of water was prohibited, no advance was made in this direction.
the phosphatic chalk and the phosphate sand, the latter resulting from the decomposition of the former.
half of the state, is mainly a clay which was formed by the glacial pulverizing of limestone and shale and is still forming from the decomposition of fragments of these substances.
there is some clay formed mainly by the decomposition of slate.
Other constituents are cholesterol (0.461.32%), traces of calcium, magnesium, sodium, chlorine and bromine, and various aliphatic amines which are really secondary products, being formed by the decomposition of the cellular tissue.
It is obtained by the dry distillation of nitrogenous vegetable and animal products; by the reduction of nitrous acid and nitrites with nascent hydrogen; and also by the decomposition of ammonium salts by alkaline hydroxides or by slaked lime, the salt most generally used being the chloride (sal-ammoniac, q.v.) thus 2NH 4 C1+Ca(OH) 2 =CaC1 2 +2H 2 O+2NH 3.
At a red heat ammonia is easily decomposed into its constituent elements, a similar decomposition being brought about by the passage of electric sparks through the gas.
Silberrad assigns the formula NH 3 ï¿½NI 3 to the compound, and explains the decomposition as taking place, 2NH3ï¿½N13+ 6Zn (C2H5)2 = 6ZnC 2 H 5 ï¿½I+2NH 3 +2N(C 2 H 5) 3.
It gradually turns yellow on standing in moist air, owing to decomposition with liberation of iodine.
It possesses a strong ammoniacal smell, and on digestion with alcohol the carbamate is dissolved and a residue of ammonium bicarbonate is left; a similar decomposition taking place when the sesquicarbonate is exposed to air.
The aqueous solutions of all the carbonates when boiled undergo decomposition with liberation of ammonia and of carbon dioxide.
Ammonium nitrate, NH 4 NO 3, is prepared by neutralizing nitric acid with ammonia, or ammonium carbonate, or by double decomposition between potassium nitrate and ammonium sulphate.
Fluorides can be readily detected by their power of etching glass when warmed with sulphuric acid; or by warming them in a glass tube with concentrated sulphuric acid and holding a moistened glass rod in the mouth of the tube, the water apparently gelatinizes owing to the decomposition of the silicon fluoride formed.
mesentericus do not develop below 15° C.; but if it be introduced into the alimentary canal of a child the spores will rapidly multiply, and in such cases large quantities of gas, giving rise to flatulency, will be formed, and possibly also poisonous decomposition products of albuminoid matter.
The graphite veins in the older crystalline rocks are probably akin to metalliferous veins and the material derived from deep-seated sources; the decomposition of metallic carbides by water and the reduction of hydrocarbon vapours have been suggested as possible modes of origin.
Meyer, Ber., 1876, 9, P. 543), C3H7NH 2 +HNO 2 =N 2 +2H 2 O+C 3 H 6; by the electrolysis of the alkali salts of saturated dicarboxylic acids; by the decomposition of 0-haloid fatty acids with sodium carbonate, CH 3 CHBr CH(CH 3) CO 2 H =CO 2 -1-HBr+CH 3 CH :CH CH 3; by distilling the barium salts of acids Cn,H 2, ,,- 2 0 2 with sodium methylate in vacuo (I.
Lavoisier (1781-1788) first proved it to be an oxide of carbon by burning carbon in the oxygen obtained from the decomposition of mercuric oxide.
It is a constituent of the minerals cerussite, malachite, azurite, spathic iron ore, calamine, strontianite, witherite, calcite aragonite, limestone, &c. It may be prepared by burning carbon in excess of air or oxygen, by the direct decomposition of many carbonates by heat, and by the decomposition of carbonates with mineral acids, M2C03+2HC1=2MCl-FH 2 O+CO 2.
It Is Also Formed When Sulphur Trioxide Reacts With Carbon Bisulphide At 100° C., Cs2 3S03 =Cos 4So 2, And By The Decomposition Of Ethyl Potassium Thiocarbonate With Hydrochloric Acid, Co(0C2115)Sk Hc1= Cos Kc1 C 2 H 5 Oh.
66, p. 97) effected the same decomposition with charcoal at a white heat.
Potassium hydroxide or caustic potash, KOH, formerly considered to be an oxide but shown subsequently to be a hydroxide of potassium, may be obtained by dissolving the metal or monoxide in water, but is manufactured by double decomposition from potassium carbonate and slaked lime: K 2 CO 3 -E-Ca(OH) 2 =2KOH+CaC03.
If wet it oxidizes the products of decomposition.
Iodine may also be prepared by the decomposition of an iodide with chlorine, or by heating a mixture of an iodide and manganese dioxide with concentrated sulphuric acid.
The salts of this acid, known as cyanides, may be prepared by the action of cyanogen or of gaseous hydrocyanic acid on a metal; by heating the carbonates or hydrooxides of the alkali metals in a current of hydrocyanic acid; by heating alkaline carbonates with carbon in the presence of free nitrogen: BaCO 3 + 4 C + N2 = Ba(NC) 2 + 3C0; by ignition of nitrogenous organic substances in the presence of alkaline carbonates or hydroxides; or by processes of double decomposition.
Besides these, other double cyanides are known which do not suffer such decomposition, the heavy metal present being combined with the cyanogen radical in the form of a complexion.
They are mostly colourless liquids which boil without decomposition, or solids of low melting point.
In this reaction a glycerol ester is formed as an intermediate product, and undergoes decomposition by the water which is also produced at the same time.
15, p. 371), a somewhat similar decomposition being shown by chloral and aqueous potash (J.
It is a liquid which boils in vacuo at 150°, but at 192-195° C. under ordinary atmospheric pressure, with partial decomposition into carbon monoxide and ammonia.
In 1835, in a paper on "The Prismatic Decomposition of Electrical Light," he proved that sparks from different metals give distinctive spectra, which afforded a ready means of discriminating between them.
In the Piedmont Plateau and Appalachian Mountains Regions the surface soil is generally sandy, but in considerable areas the subsoil is a red clay derived largely from the decomposition of hornblende.
Benzene-azoethane, C 6 H 5 N 2 C 2 H 5, is a yellow oil which boils at about 180 C. with more or less decomposition.
The disease is characterized by the decomposition of the blood; in fact it is really a form of dropsy.
Such spectra seem to be characteristic of complex molecular structure, as they appear when compounds are raised to incandescence without decomposition, or when we examine the absorption spectra of vapours such as iodine and bromine and other cases where we know that the molecule consists of more than one atom.
It occurs free in bitter almonds, being formed by an enzyme decomposition of amygdalin.
The soil of the Territory is almost wholly a decomposition of lava, and in general differs much from the soils of the United States, particularly in the large amount of nitrogen (often more than 1.25% in cane and coffee soil, and occasionally 2.2%) and iron, and in the high degree of acidity.
A treatise on the analysis of thought (Sur la decomposition de la pensee), although sent to press, was never printed.
It may also be obtained by the decomposition of boracite with hot hydrochloric acid.
Further he prepared a large number of substances, including the chlorides and other salts of lead, tin, iron, zinc, copper, antimony and arsenic, and he even noted some of the phenomena of double decomposition.
"I do not think, therefore, that decomposing solutions or substances will be found to have (as a consequence of decomposition or arrangement for the time) any effect on the polarized ray.
Should now try non-decomposing bodies, as solid nitre, nitrate of silver, borax, glass, &c., whilst solid, to see if any internal state induced, which by decomposition is destroyed, i.e.
On the other hand, solution of mineral acids and salts conduct the current with chemical decomposition - they are called electrolytes.
Ramsay), partial decomposition into water, oxygen and nitrogen peroxide taking place.
Alumina itself is so refractory that it cannot be melted save by the oxyhydrogen blowpipe or the electric arc, and except in the molten state it is not susceptible of decomposition by any chemical reagent.
Rose also carried out experiments on the decomposition of cryolite, and expressed an opinion that it was the best of all compounds for reduction; but, finding the yield of metal to be low, receiving a report of the difficulties experienced in mining the ore, and fearing to cripple his new industry by basing it upon the employment of a mineral of such uncertain supply, Deville decided to keep to his chlorides.
Alumina dissolves readily enough in aqueous hydrochloric acid to yield a solution of the chloride, but neither this solution, nor that containing sodium chloride, can be evaporated to dryness without decomposition.
The charge was reduced by means of a 50-volt current from a Soo-kilowatt dynamo, which was passed through the furnace for 12 hours till decomposition was complete.
That this process did not depend upon electrolysis, but was simply an instance of electrical smelting or the decomposition of an oxide by means of carbon at the temperature of the electric arc, is shown by the fact that the Cowles furnace would work with an alternating current.
Natural soils consist of substances derived from the decomposition of various kinds of rocks, the bulk consisting of clay, silica and lime, in various proportions.
The urine should be allowed to putrefy, as in its decomposition a large amount of ammonia is formed, which should then be fixed by sulphuric acid or gypsum; or it may be applied to the growing crops after being freely diluted with water or absorbed in a compost heap. Liquid manures can be readily made from most of the solid manures when required, simply by admixture with water.
It is, indeed, probable that it is formed in the intestine, as a result of some decomposition as yet unknown.
7) the solid matter has become so hot that the now deoxidized iron melts, as does the slag as fast as it is formed by the union of its three constituents, the gangue, the lime resulting from the decomposition of the limestone and the ash of the fuel.
Jochem (Ber., 1901, 34, p. 3337), who arrived at the conclusion that the normal decomposition of diazonium salts by alcohols results in the formation of phenolic ethers, but that an increase in the molecular weight of the alcohol, or the accumulation of negative groups in the aromatic nucleus, diminishes the yield of the ether and increases the amount of the hydrocarbon formed.
It may be prepared by the electrolysis of acidulated water, by the decomposition of water by various metals or metallic hydrides, and by the action of many metals on acids or on bases.
The decomposition of steam by red hot iron has been studied by H.
Among other ancient buildings, situated chiefly in the old town, are the following: - the cathedral of St Peter (formerly the archiepiscopal and now the Lutheran parish church), erected in the 12th century on the site of Charlemagne's wooden church, and famous for its Bleikeller, or lead vault, in which bodies can be preserved for a long time without suffering decomposition; the church of St Ansgarius, built about 1243, with a spire 400 ft.
Dimethyl sulphate, (CH3)2S04, is a colourless liquid which boils at 187 °-188° C., with partial decomposition.
Ethyl nitrate, C2H5.0N02, is a colourless liquid which boils at 86.3° C. It is prepared by the action of nitric acid on ethyl alcohol (some urea being added to the nitric acid, in order to destroy any nitrous acid that might be produced in secondary reactions and which, if not removed, would cause explosive decomposition of the ethyl nitrate).
Other authors have sought the origin of the diamond in the action of the hydrated magnesian silicates on hydrocarbons derived from bituminous schists, or in the decomposition of metallic carbides.
Before its fall the leaf has become dry owing to loss of water and the removal of the protoplasm and food substances to the stem for use next season; the red and yellow colouring matters are products of decomposition of the chlorophyll.
This conception led Kekule to his "closed-chain" or "ring" theory of the constitution of benzene which has been called the "most brilliant piece of prediction to be found in the whole range of organic chemistry," and this in turn led in particular to the elucidation of the constitution of the "aromatic compounds," and in general to new methods of chemical synthesis and decomposition, and to a deeper insight into the composition of numberless organic bodies and their mutual relations.
In organic chemistry he published papers on the decomposition of ammonium oxalate, with formation of oxamic acid, on amyl alcohol, on the cyanides, and on the difference in constitution between nitric and sulphuric ether.
Chalcedony occurs as a secondary mineral in volcanic rocks, representing usually the silica set free by the decomposition of various silicates, and deposited in cracks, forming veins, or in vesicular hollows, forming amygdales.
The brown tints often seen in glazed objects are almost always the result of the decomposition of green glazes containing iron.
It is not surprising that the chemical substances produced in it by the decomposition of its living material should not be of a nature indifferent for muscular life.
It crystallizes in deliquescent prisms and melts with partial decomposition at 119-120° C. It behaves as a ketonic acid, being reduced in aqueous solution by sodium amalgam to tartronic acid, and also combining with phenylhydrazine and hydroxylamine.
At times sodium sulphate is added to the brine, producing sodium chloride and magnesium sulphate by double decomposition with the magnesium chloride.
Thallous sulphate, T1 2 SO 4, forms rhombic prisms, soluble in water, which melt at a red heat with decomposition, sulphur dioxide being evolved.
It crystallizes in needles which melt at 190° C. (with decomposition), and is readily soluble in hot water.
The actual decomposition of the chlorate is not settled definitely; the following equations give the results obtained by P. F.
Manganous Nitrate, Mn(NO 3) 2.6H 2 0, obtained by dissolving the carbonate in nitric acid and concentrating the solution, crystallizes from nitric acid solutions in long colourless needles, which melt at 25.8° C. and boil at 129.5° C. with some decomposition.
Considerations of weight had long prevented Lavoisier from accepting this doctrine, but he was now able to explain the process fully, showing that the hydrogen evolved did not come from the metal itself, but was one product of the decomposition of the water of the dilute acid, the other product, oxygen, combining with the metal to form an oxide which in turn united with the acid.
THE Leblanc Process The Leblanc process, which was invented by Nicolas Leblanc about 1790, begins with the decomposition of sodium chloride by sulphuric acid, by, which sodium sulphate and hydrochloric acid are produced.
The principles of the condensation, that is of converting the gaseous hydrochloric acid given off during the decomposition of common salt into a strong solution of this gas in water, can be summarized in a few words.
On a small scale it is possible to push the decomposition as far as 90% of the hydrochloric acid, but on the large scale only at most 60% is reached.
The bleaching-powder casks must be kept in a dry place, as cool as possible, and never exposed to the direct rays of the sun, in order to prevent a decomposition which now and then has even led to explosions.
The leading reaction of this process is the mutual decomposition of ammonium bicarbonate and sodium chloride: NaCI+NH 4 HCO 3 = NaHCO 3 -1-NH 4 C1.
(I) The Diaphragm process is probably the only one employed at present for the decomposition of potassium chloride, and it is also used for sodium chloride.
Phosphorus pentachloride converts them into alkyl chlorides, a similar decomposition taking place when they are heated with the haloid acids.
It has usually been formed by the decomposition in situ of the rock on which it rests, but it is often broken up and re-deposited elsewhere.
The reason why two levels are employed is that sometimes crystals are formed by the decomposition of the glass which cause the bubble to stick at different points and so give false readings.
Nickel sesquioxide, N1203, is formed when the nitrate is decomposed by heat at the lowest possible temperature, by a similar decomposition of the chlorate, or by fusing the chloride with potassium chlorate.
When perfectly pure, the hexachloride is stable even in moist air, but the presence of an oxychloride brings about energetic decomposition; similarly water has no action on the pure compound, but a trace of the oxychloride occasions sudden decomposition into a greenish oxide and hydrochloric acid.
It is unaffected by moist air or cold water, and even when boiled with water the decomposition is incomplete.
It crystallizes in shining leaflets, which melt at 52° C. and boil at 245° C. (with decomposition), and is volatile in a current of steam.
The residual magnesium chloride of the ammonia-soda process is evaporated until it ceases to give off hydrochloric acid, and is then mixed with more magnesia; the magnesium oxychloride formed is broken into small pieces and heated in a current of air, when it gives up its chlorine, partly in the uncombined condition and partly in the form of hydrochloric acid, and leaves a residue of magnesia, which can again be utilized for the decomposition of more ammonium chloride (W.
Decomposition takes place and the issuing gas contains 18-20% of chlorine.
The solution of chlorine in water, when freshly prepared, possesses a yellow colour, but on keeping becomes colourless, on account of its decomposition into hydrochloric acid and oxygen.
The chlorides of the nonmetallic elements are usually volatile fuming liquids of low boilingpoint, which can be distilled without decomposition and are decomposed by water.
Sulphur, phosphorus, carbon compounds, and the alkali metals react violently with the gas, taking fire with explosive decomposition.
Balard determined the volume composition of the gas by decomposition over mercury on gentle warming, followed by the absorption of the chlorine produced with potassium hydroxide, and then measured the residual oxygen.
The acid is only known in aqueous solution, and only dilute solutions can be distilled without decomposition.
Further concentration leads to decomposition, with evolution of oxygen and formation of perchloric acid.
Roscoe, pure perchlo: is acid distils over at first, but if the distillation be continued a white crystalline mass of hydrated perchloric acid, HC104 H20, passes over; this is due to the decomposition of some of the acid into water and lower oxides of chlorine, the water produced then combining with the pure acid to produce the hydrated form.
It crystallizes in plates which melt at 120° C., and distils without decomposition.
They may be prepared by dissolving or suspending a metallic oxide or hydroxide in water and saturating the solution with chlorine; by double decomposition; or by neutralizing a solution of chloric acid by a metallic oxide, hydroxide or carbonate.
The modern process consists in the electrolysis of a hot solution of potassium chloride, or, preferably, the formation of sodium chlorate by the electrolytic method and its subsequent decomposition by potassium chloride.
The word usage examples above have been gathered from various sources to reflect current and historial usage. They do not represent the opinions of YourDictionary.com.