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.
Heated rather below 300° C. amber suffers decomposition, yielding an "oil of amber," and leaving a black residue which is known as "amber colophony," or "amber pitch"; this forms, when dissolved in oil of turpentine or in linseed oil, "amber varnish" or "amber lac."
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.
This is the absorption of elaborated compounds from their environment, by whose decomposition the potential energy expended in their construction can be liberated.
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.
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.
Uracil and its homologues may be obtained in many cases from the hydrouracils by the action of bromine, and subsequent elimination of the elements of hydrobromic acid; or by the condensation of aceto-acetic ester and related substances with urea, thiourea, guanidine, &c. Uracil, C4H402N2, crystallizes in colourless needles, is soluble in hot water and melts with decomposition at 335° C. Hydrouracil, C4H602N2, is obtained by the action of bromine and caustic alkalis on succinamide (H.
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.
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.
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.
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.
Potash soap with the same reagent undergoes double decomposition - a proportion being changed into a soda soap with the formation of potassium chloride.
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.
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.
When phenol is passed through a red-hot tube a complex decomposition takes place, resulting in the formation of benzene, toluene, naphthalene, &c. (J.
Its heat of decomposition into its elements.
Of mercury it boils at 170° C. In an atmosphere of steam it distils without decomposition under ordinary barometric pressure.
Glycerin acts as a preservative against decomposition, owing to its antiseptic qualities, which also led to its being employed to preserve untanned leather (especially during transit when exported, the hides being, moreover, kept soft and supple); to make solutions of gelatin, albumen, gum, paste, cements, &c. which will keep without decomposition; to preserve meat and other edibles; to mount anatomical preparations; to preserve vaccine lymph unchanged; and for many similar purposes.
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 hydrocarbon C20H42, for example, might be resolved into C5H12+C15H30, or CEH14+C14H28, or C7H16 +C13H26, &c., the general equation of the decomposition being C„1-1 27, ± 2 (paraffin) =G_rH2(, - P)+2 (paraffin)+C P H 2 n (olefine).
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.
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.