How to use Carbonic in a sentence
Carbonic acid is taken from the water and synthesized (by the mediation of light energy) into carbohydrate.
The quantities of oxygen and carbonic acid in the sea are nearly constant so far as we can determine.
The presence of carbonic acid in a water does not affect its action on lead.
There is reason to believe that carbonic acid is always one of these waste products, while the others contain the remainder of the carbon, the nitrogen, the hydrogen and the other elements which may enter into the composition of the protoplasm.
Another fact of considerable technical importance is, that the various races of yeast show considerable differences in the amount and proportion of fermentation products other than ethyl alcohol and carbonic acid which they produce.Advertisement
It is somewhat readily oxidized; nitric acid gives carbonic and oxalic acids, and chromic acid, carbonic and acetic acids.
This is not by the supply of food alone, but also by the withdrawal of carbonic acid from the atmosphere, by which vegetation maintains the composition of the air in a state fit for the support of animal life.
The chief interest of the place centres in its brine springs which are largely impregnated with carbonic acid gas and oxide of iron, and are efficacious in chronic catarrh of the respiratory organs, in liver and stomach disorders and women's diseases.
Further, the ocean and the atmosphere stand in equilibrium with each other; if there is excess of carbonic acid anywhere in the sea it is absorbed by the atmosphere and vice versa, and so also with the oxygen.
The water in shallow seas, off the shores of islands or in lagoons, is saturated with calcium bicarbonate and if the amount of carbonic acid in solution be reduced by any means, normal carbonate must be precipitated.Advertisement
It forms colourless transparent crystals, soluble in one and a half parts of cold water and in eight parts of alcohol, which on exposure to ordinary air become opaque through absorption of carbonic acid, which forms a crust of basic carbonate.
By the joint action of water and air, thallium, lead, bismuth are oxidized, with formation of more or less sparingly soluble hydroxides (ThHO, PbH 2 O 2, BiH303), which, in the presence of carbonic acid, pass into still less soluble basic carbonates.
The carbonic acid gas injected into the highly limed juice in the saturators is made by the calcination of limestone in a kiln provided with three cleaning doors, so arranged as to allow the lime to be removed simultaneously from them every six hours.
Taking magnesia alba, which he distinguished from limestone with which it had previously been confused, he showed that on being heated it lost weight owing to the escape of this fixed air (named carbonic acid by Lavoisier in 1781), and that the weight was regained when the calcined product was made to reabsorb the fixed air with which it had parted.
The first difficulty was to make it sufficiently light in relation to the power its machinery could develop; and several machines were built in which trials were made of steam, and of compressed air and carbonic acid gas as motive agents.Advertisement
It can develop vacuoles, or rather fine bubbles of carbonic acid gas in its cytoplasm, to float up to the surface of the water.
Murray and Renard ascribe this to the greater abundance of carbonic acid in the deeper water, which aided by the increased pressure adds to the solvent power of the water for carbonate of lime.
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.
The water of the ocean, like any other liquid, absorbs a certain amount of the gases with which it is in contact, and thus sea-water contains dissolved oxygen, nitrogen and carbonic acid absorbed from the atmosphere.
One portion is used for determining the oxygen and nitrogen, the other for the carbonic acid.Advertisement
The former determination is made by driving out the dissolved gases from solution and collecting them in a Torricellian vacuum, where the volume is measured after the carbonic acid has been removed.
In the second portion the carbonic acid is driven out by means of a current of hydrogen, collected over mercury and absorbed by caustic potash.
The facts regarding carbonic acid in sea-water are even less understood, for here we have to do not only with the solution of the gas but also with a chemical combination.
Since 1851 it has been known that all sea-water has an alkaline reaction, and Torniie defined the alkalinity of sea-water as the amount of carbonic acid which is necessary to convert the excess of bases into normal carbonate.
The alkalinity of North Atlantic water of 35 per mille salinity is 26.86 cc. per litre, corresponding to a total amount of carbonic acid of 49 07 cc. According to the researches of August Krogh,' the alkalinity is greatly increased by the admixture of land water.Advertisement
Carbonic acid passes from the atmosphere into the ocean as soon as its tension in the latter is the smaller; hence in this respect the ocean acts as a regulator.
The amount of carbonic acid in solution may also be increased by submarine exhalations in regions of volcanic disturbance, but it must be remembered that the critical pressure for this gas is 73 atmospheres, which is reached at a depth of 400 fathoms, so that carbonic acid produced at the bottom of the ocean must be in liquid form.
The respiration of marine animals in the depths of deep basins in which there is no circulation adds to the carbonic acid at the expense of the dissolved oxygen.
Buchanan on the " Challenger " were vitiated by the incompleteness of the method employed, but they are none the less of value in showing clearly that the waters of the far south of the Indian Ocean are relatively rich in carbonic acid and the tropical areas deficient.
When coal is heated to redness out of contact with the air, the more volatile constituents, water, hydrogen, oxygen, and nitrogen are in great part expelled, a portion of the carbon being also volatilized in the form of hydro carbons and carbonic oxide,-the greater part, however, remaining behind, together with all the mineral matter or ash, in the form of coke, or, as it is also called, " fixed carbon."
The latter observer found the gases given off tion of gas by coal from the district of Newcastle and Durham evolved by to contain carbonic acid, marsh gas or light carburetted coal.
They consist almost entirely of marsh gas, with only a small quantity of carbonic acid, usually under 1%, and from i to 4% of nitrogen.
The air was continually returned and circulated until it was too much contaminated with carbonic acid to be further used, a condition which limited the use of the apparatus to a very short period.
The newer forms are based upon the principle, first enunciated by Professor Theodor Schwann in 1854, of carrying compressed oxygen instead of air, and returning the products of respiration through a regenerator containing absorptive media for carbonic acid and water, the purified current being returned to the mouth with an addition of fresh oxygen.
In another form of apparatus advantage is taken of the property possessed by sodium-potassium peroxide of giving off oxygen when damped; the residue of caustic soda and potash yielded by the reaction is used to absorb the carbonic acid of the expired air.
When the coal is fired by the blast of an explosion it is often necessary to isolate the mine completely by stopping up the mouths of the pits with earth, or in extreme cases it must be flooded with water or carbonic acid before the fire can be brought under.
Oxidation gives formaldehyde, formic acid and carbonic acid; chlorine and bromine react, but less readily than with ethyl alcohol.
The soluble trimetallic salts are decomposed by carbonic acid into a dimetallic salt and an acid carbonate.
Being soluble in water containing carbonic acid or organic acids it may be readily removed in solution, and may thus furnish plants and animals with the phosphates required in their structures.
Thus, for instance, sound is refracted towards the perpendicular when passing into air from water, 0 or into carbonic acid gas from air; the converse is the case when the passage takes place the opposite way.
Most natural waters contain it dissolved in carbonic acid; this confers "temporary hardness" on the water.
It is insoluble in water; slightly soluble in solutions of carbonic acid and common salt, and readily soluble in concentrated hydrochloric and nitric acid.
Aix has thermal springs, remarkable for their heat and containing lime and carbonic acid.
The solution of the gas in water shows a faintly acid reaction and is supposed to contain carbonic acid, H2C03.
The solid must be at once bottled, because it attracts the moisture and carbonic acid of the air with great avidity and deliquesces.
Potassium bicarbonate, Khco 3, is obtained when carbonic acid is passed through a cold solution of the ordinary carbonate as long as it is absorbed.
The flux is moistened with water and exposed to a current of carbonic acid, which, on account of the condensing action of the charcoal, is absorbed with great avidity.
With these exceptions, the simple cyanides are readily decomposed even by carbonic acid, free prussic acid being liberated.
In his widely used method for the quantitative determination of carbonic acid the gaseous mixture is shaken up with baryta or lime water of known strength and the change in alkalinity ascertained by means of oxalic acid.
Beyond variable quantities of moisture and traces of carbonic acid, hydrogen, ammonia, &c., the only constituents recognized were nitrogen and oxygen.
When limonite is dehydrated and deoxidized in the presence of carbonic acid, it may give rise to chalybite.
Many fossils are mineralized with pyrites, which has evidently been reduced by the action of decomposing organic matter on a solution of ferrous sulphate, or perhaps less directly on ferrous carbonate dissolved in water containing carbonic acid, in the presence of certain sulphates.
The next great improvement in blast-furnace practice came in 1811, when Aubertot in France used for heating steel the furnace gases rich in carbonic oxide which till then had been allowed to burn uselessly at the top of the blast furnace.
In carrying out this process the castings are packed in a mass of iron oxide, which at this temperature gradually removes the fine or " temper " graphite by oxidizing that in the outer crust to carbonic oxide, whereon the carbon farther in begins diffusing outwards by " molecular migration," to be itself oxidized on reaching the crust.
Part of the resultant carbonic acid is again deoxidized to carbonic oxide by the surrounding fuel, CO 2 + C = 2C03 and the carbonic oxide thus formed deoxidizes more iron oxide, &c. As indicated in fig.
Now the heat developed by the combustion of coke to carbonic oxide with cold air containing the usual quantity of moisture, develops a temperature only slightly above this critical point; and it is only the heat represented by this narrow temperature-margin that is available for doing this critical work of fusion and deoxidation.
As the essential difference between cast iron on one hand and wrought iron and steel on the other is that the former contains necessarily much more carbon, usually more silicon, and often more phosphorus that are suitable or indeed permissible in the latter two, the chief work of all these conversion processes is to remove the excess of these several foreign elements by oxidizing them to carbonic oxide CO, silica S102, and phosphoric acid P 2 0 5, respectively.
It oxidizes the carbon also, which escapes in purple jets of burning carbonic oxide.
Later, when most of it has been oxidized, the carbon begins to oxidize to carbonic oxide, which in turn burns.
Part of the carbon of this spiegeleisen unites with the oxygen occluded in the molten iron to form carbonic oxide, and again a bright flame, greenish with manganese, escapes from the converter.
The oxidation of the foreign elements must be very slow, lest the effervescence due to the escape of carbonic oxide from the carbon of the metal throw the charge out of the doors and ports of the furnace, which itself must be shallow in order to hold the flame down close to the charge.
A cold lump of ore chills the slag immediately around it, just where its oxygen, reacting on the carbon of the metal, generates carbonic oxide; the slag becomes cool, viscous, and hence easily made to froth, just where the froth-causing gas is evolved.
The ebullition from the formation of carbonic oxide puffs up the resultant phosphoric slag enough to make most of it run out of the furnace, thus both removing the phosphorus permanently from danger of being later deoxidized and returned to the steel, and partly freeing the bath of metal from the heat-insulating blanket of slag.
Where the carbon, in thus diffusing inwards, meets particles of the slag, a basic ferrous silicate which is always present in wrought iron, it forms carbonic oxide, FeO+ C = Fe+CO, which puffs the pliant metal up and forms blisters.
It is practically unattainable in the open-hearth furnace, because here the oxygen of the furnace atmosphere indirectly oxidizes the carbon of the metal which is kept boiling by the escape of the resultant carbonic oxide.
These additions seem to act in part by deoxidizing the minute quantity of iron oxide and carbonic oxide present, in part by increasing the solvent power of the metal for gas, so that even after freezing it can retain in solution the gas which it had dissolved when molten.
Four miles to the north is the Lacus Palicorum, a small lake in a crater, which still sends up carbonic acid gas.
On the other hand, certain undoubted animals (Stentor, Hydra, Bonellia) are provided with a green colouring matter by means of which they make use of atmospheric carbonic acid.
In all cases the loss of the colouring matter is associated with an incapacity to take up carbon from so simple a compound as carbonic acid.
Although algae generally are able to use carbonic acid gas as a, source of carbon, some algae, like certain of the higher plants, are capable of utilizing organic compounds for this purpose.
By virtue of the possession of chlorophyll all algae are capable of utilizing carbonic acid gas as a source of carbon in the presence of sunlight.
Subsequent hardening of the mortar is caused by the gradual absorption of carbonic acid from the air by the lime, a skin of carbonate of lime being formed; but the action is superficial.
As it descends it reaches a part of the kiln where the temperature is higher; here the carbonic acid of the carbonate of lime, and the combined water of the clay are driven off, and the resulting lime begins to act chemically on the dehydrated clay.
It crystallizes from its solution in long yellow needles, T10H or T10H-+H 2 0, which dissolve readily in water, forming an intensely alkaline solution, which acts as a caustic, and like it greedily absorbs carbonic acid from the atmosphere.
Sometimes they are made, not from soda-ash, but from Leblanc soda-liquor before " finishing " the ash, or from the crude bicarbonate of the ammonia-soda process by prolonged boiling, until nearly half of the carbonic acid has been expelled.
Formerly bicarbonate of soda was made from Leblanc sodacrystals by the action of carbonic acid, but this article is now almost exclusively made in the ammonia-soda process.
Sulphur and salt springs occur on the slopes of Cherimai, and near Palimanan there is a cavernous hole called Guwagalang (or Payagalang), which exhales carbonic acid gas, and is considered holy by the natives and guarded by priests.
The secondary fermentation proceeds slowly and the carbonic acid formed is allowed to escape by way of the bung-hole, which in order to prevent undue access of air is kept lightly covered or is fitted with a water seal, which permits gas to pass out of the cask, but prevents any return flow of air.
As regards the latter, indeed, it is nowadays held that it is at its best within a very short period of the vintage, and that when the characteristic slight " prickling " taste due to carbonic acid derived from the secondary fermentation has disappeared, the wine has lost its attraction for the modern palate.
The micro-organism splits up the alcohol of the wine and some of the other constituents, forming carbonic acid and water.
It is very likely that the discovery of the utility of cork for stoppering led to the invention of effervescent wine, the most plausible explanation being that Dom Perignon closed some bottles filled with partially fermented wine, with the new material, and on opening them later observed, the effects produced by the confined carbonic acid gas.
In the spring-time, shortly after bottling, the rise in temperature produces a secondary fermentation, and this converts the sugar into alcohol and carbonic acid.
Indeed, many connoisseurs hold that when a Moselle ceases to show signs of the somewhat prolonged secondary fermentation, characterized by the slight prickling sensation produced on the palate (caused by the presence of bubbles of carbonic acid gas in the wine), that it has passed its best.
Its remarkable efficacy in healing ulcers of the mouth - for which it is the specific - has been ascribed to a decomposition effected by the carbonic acid which is given off from these ulcers.
Geissler (1815-1879) containing air, carbonic acid, hydrogen, &c., under a pressure of one or two millimetres, exhibit beautiful appearances when traversed by the high tension current produced by the secondary circuit of an induction coil.
Copper is not affected by exposure in dry air, but in a moist atmosphere, containing carbonic acid, it becomes coated with a green basic carbonate.
Somewhat similar effects are produced by so-called wave-baths, and at Nauheim, although the fresh movement of the water against the surface of the body is much less than in the sea, yet its stimulating effect is greatly increased by the presence of carbonic acid in it.
While water containing much saline matter, and more especially water containing free carbonic acid, has a very stimulating action upon the skin, mud has a sedative effect, so that in a mud-bath one feels a pleasant soothing sensation as if bathing in cream.
The place, which was formerly called Rehme, owes its development to the discovery in 1830 of its five famous salt springs, which are heavily charged with carbonic acid gas.
Quinine hydrochloride circulates in the alkaline blood without precipitation, probably owing to the presence of carbonic acid in the blood.
This conclusion is further confirmed by the observation that the amount of carbonic acid excreted by the lungs is also diminished.
Of the insoluble salts we may notice the tannate, the propionic acid ester (euquinine) and carbonic acid ester (aristoquin), the salicylic acid ester.
Thus oxygen gas, at the end of the 18th century, was known as dephlogisticated air, nitrogen or azote as phlogisticated air, hydrogen as inflammable air, carbonic acid gas as fixed air.
One of the springs gives off carbonic acid gas and another contains a considerable proportion of lithia salts.
This is explained by the fact that the Chalk fissures are almost invariably rounded and enlarged by the erosion of carbonic acid carried from the surface by the water passing through them.
These fissures take the place of the streams in an impermeable area, and those beneath the valleys must obviously be called upon to discharge more water from the surface, and thus be brought in contact with more carbonic acid, than similar fissures elsewhere.
It contains, as its principal constituents, ammonia, partly combined with carbonic acid and sulphuretted hydrogen to form compounds which are decomposed on boiling, with evolution of ammonia gas, and partly combined with stronger acids to form compounds which require to be acted upon by a strong alkali before the ammonia contained in them can be liberated.
These strata are practically stagnant, deficient in oxygen and surcharged with carbonic acid.
The accumulation of carbonic acid in the breathed air would also have a similar arrestive power over destructive assimilation.
Among other interesting developments is the manufacture of liquid carbonic acid gas procured from natural gas springs beside the Eyach, a tributary of the Neckar.
Sulphur springs and boiling mud lakes are also general in the volcanic districts; and in places there are carbonic acid springs, these more especially on the peninsula of Snaefellsnes, north of Faxafloi.
Its waters, which are ferruginous and largely charged with carbonic acid gas, are of use in nervous and rheumatic disorders.
Acids, other than carbonic, may promote rusting; this is particularly the case with ironwork exposed to the acids - sulphurous, nitric, &c. - contained in smoke.
Since then the ammonia compression machine has been most widely adopted, though the carbonic acid machine, also compression, which was first made in 1880 from Linde's designs, is now used to a considerable extent, especially on board ship.
The refrigerating liquid (ether, sulphur dioxide, anhydrous ammonia, or carbonic acid) passes from the bottom of the condenser through the regulating valve into the refrigerator in a continuous stream.
The results show that the loss is least in the case of anhydrous ammonia and greatest in the case of carbonic acid.
When the critical point is reached the value of r disappears altogether, and a carbonic-acid machine is then dependent for its refrigerating effect on the reduction in temperature produced by the internal work performed in expanding the gaseous carbonic acid from the condenser pressure to that in the refrigerator.
The expanded vapour enters the refrigerator at a temperature below that of the substance to be cooled, and whatever cooling effect is produced is brought about by the superheating of the vapour, the result being that above the critical point of carbonic acid the difference T2-T2 is increased and the efficiency of the machine is reduced.
Some of the principal physical properties of sulphurous acid, anhydrous ammonia, and carbonic cold are given in Tables III., IV.
In an ammonia machine copper and copper alloys must be avoided, but for carbonic acid they are not objectionable.
In the meat trade between the River Plate, the United States, Canada and Great Britain, ammonia or carbonic acid machines are now exclusively used, but for the Australian and New Zealand frozenmeat trade compressed-air machines are still employed to a small extent.
When dissolved in water, however, carbonic acid gas is a gentle stimulant to the mouth, stomach and bowel, the mixture being absorbed more rapidly than plain water; hence its greater value in assuaging thirst.
Mineral waters act in the same way, but their effects are very much modified by, and depend largely upon, other constituents, such as alkaline salts, iron, arsenic, sulphides, carbonic acid, &c.
Fluorine and its compounds are often supposed to have been among the agencies which produce this change, but more probably carbonic acid played the principal role.
Gummic acid reddens litmus, its reaction being about equal to carbonic acid.
Owing to the conditions of the work, which require the maintenance of a sensibly reducing atmosphere, they contain a very notable proportion of carbonic oxide, and are drawn off by large wrought iron tubes near the top of the furnace and conveyed by branch pipes to the different boilers and air-heating apparatus, which are now entirely heated by the combustion of such gases, or mixed with air and exploded in gas engines.
When two elements form more than one compound, as is the case with oxygen and carbon, he assigned to the compound which he thought the more complex an atom made up of two atoms of the one element and one atom of the other; the diagram for carbonic acid illustrates this, and an extension of the same plan enabled him to represent any compound, however complex its structure.
In this connexion Pasteur showed that ioo parts of cane sugar on inversion gave 105.4 parts of invert sugar, which, when fermented, yielded 51.1 parts alcohol, 49.4 carbonic acid, o.
Only the " free " carbonic acid and that of the bicarbonate can be utilized in the process of photosynthesis by the diatoms and alga.
The carbonic acid is taken from solution and then bicarbonate (usually that of magnesium) dissociates into carbonic acid and normal carbonate, and the process of photosynthesis ceases when there is no more bicarbonate in solution.
This corresponds to an increased alkalinity represented by about 2 c.c. of N/ 100 standard alkali, and that difference means that the carbon of about 8.8 milligrammes of carbonic acid has been built up (by photosynthesis) into carbohydrate during the period during which the change in alkalin ity proceeded.
The former gas is continually being evolved by the plants and absorbed by the animals, and precisely the reverse actions occur in the case of carbonic acid.
Therefore an increase in photosynthesis caused by the multiplication of plant microorganisms will lead to the precipitation of calcium carbonate, for carbonic acid will be withdrawn from solution to take part in carbohydrate synthesis by the plants.
Denitrifying bacteria will raise the alkalinity (or reduce the H-ion concentration) by forming ammonia, which will combine with the carbonic acid in solution and so throw down normal carbonate of lime.
Iron, when exposed to moisture and air, "rusts"; but this process never takes place in the absence of air, and it is questionable whether it ever sets in in the absence of carbonic acid (see Rust).
Priestley and Lavoisier, at the close of the 18th century, made possible the scientific study of plant-nutrition, though Jan Ingenhousz in 1779 discovered that plants incessantly give out carbonic acid gas, but that the green leaves and shoots only exhale oxygen in sunlight or clear daylight, thereby indicating the distinction between assimilation of carbonic acid gas (photosynthesis) and respiration.
The carbon of the pig iron, burning as it does only to carbonic oxide within the converter, does not by itself generate a temperature high enough for the needs of the process.
The enormous extension of surface also facilitates the absorption of energy from the environment, and, to take one case only, it is impossible to doubt that some source of radiant energy must be at the disposal of those prototrophic forms which decompose carbonates and assimilate carbonic acid in the dark and oxidize nitrogen in dry rocky regions where no organic materials are at their disposal, even could they utilize them.
Crace-Calvert in 1871 showed that the carbon dioxide of the atmosphere was a factor; and in 1888 Crum Brown published the theory - termed the "carbonic acid theory" - that water and carbon dioxide react with iron to form ferrous carbonate and hydrogen, the ferrous carbonate being subsequently oxidized by moist oxygen to ferric hydrate and regenerating carbon dioxide, which again reacts with more iron.
The Method is done in a wraparound style frame and has optically corrected carbonic lenses that provide 100 percent UVA and UVB protection.
A TR90 Grilamid frame, TLT carbonic lenses and a medium fit completes this $80.00 look.
For lenses, polycarbonate or carbonic materials are commonly used for their durability.
The source of the carbon of organic tissues is carbonic acid; that of the nitrogen in the proteids is the nitrates, nitrites and salts of ammonia dissolved in sea-water; the material of the shells or other skeletons is the silica, phosphate and calcium of the salts of sea-water (and, in rare cases, the salts of strontium).
Carbonic acid is the most abundant and it may be contained in sea-water in the proportion of about 50 milligrammes per litre (that is, 50 per million).
When carbonic acid is present the dissolved oxide is soon precipitated as basic carbonate, so that the corrosion of the lead becomes continuous.
Sodium amalgam converts it into formic acid; whilst with alcohol it yields the normal carbonic ester.
Water and carbonic acid are synthesized, under the action of sunlight, to form sugar, starch or some other carboh y drate and this is then combined with simple nitrogenous salts to form proteid.
Pasteur found that, when cane sugar was fermented by yeast, 49.4% of carbonic acid and 51.1% of alcohol were produced; with expressed yeast juice cane sugar yields 47% of carbonic acid and 47.7% of alcohol.
He determined the percentages of carbon, hydrogen and oxygen in the sugar and in the products of fermentation, and concluded that sugar in fermenting breaks up into alcohol, carbonic acid and acetic acid.
Now dead animal substance and the excreta of animals decompose in the long run into carbonic acid, water and mineral salts, and so there is a continual destruction of animal substance both on the land and in the sea.
That is, the concentration of H-ions decreases and that of the HO-ions increases; the water becomes more alkaline because the carbonic acid of the bicarbonate has been abstracted by the phytoplankton to the extent that normal carbonate is left.
The dead bodies of organisms fall down from the surface and are slowly resolved into products of putrefaction, which gradually pass into the mineral forms, nitrates, carbonic acid and ash.
Iron, when exposed to moisture and air, "rusts"; but this process never takes place in the absence of air, and it is questionable whether it ever sets in in the absence of carbonic acid.
This is a closed vessel, into which carbonic acid gas (produced as described hereafter) is forced, and combining with the lime in the juice forms carbonate of lime.
All of this is not available, for carbonic acid is present as such in solution, as bicarbonate (of magnesium mainly) and as normal carbonate.
Mercury, if pure, and all the "noble" metals (silver, gold, platinum and platinum-metals), are absolutely proof against water even in the presence of oxygen and carbonic acid.
The principal improvement made of recent years in this portion of the process has been the construction of pipes through which the carbonic acid gas is injected into the juice in such a manner that they can be easily withdrawn and a clean set substituted.
The fouling of the air that results from the steam-engine, owing to the production of carbonic acid gas and of sulphurous fumes and aqueous vapour, is well known, and its use is now practically abandoned for underground working.