Pylorus

“ They further observed that the heat is invariably found to be greatest in the blue and bluish-grey earth; that these earths almost always contain sulphuric acid; that they contain also sulphur, iron, alum, and gypsum; and lastly, that finely-divided particles of brass-coloured pyrites are visible throughout the whole of the beds when heat exists.
“Sulphuric acid is found in the hot beds above and below that which is the hottest, but this latter manifests no acidity that is sensible to the taste.
“Sulphuretted hydrogen is continually evolved from the clays containing the brass-coloured pyrites. ”

“ These waste substances, composed chiefly of carbon and hydrogen, unite with oxygen breathed in from the air, forming carbonic acid gas and water, which are breathed out of the system. The action is a process of slow combustion, and it is principally by the heat thus evolved that the body is kept warm. As we are thus constantly taking oxygen from the air, a close room becomes unfit to live in and a supply of fresh air is indispensable. The cycle of changes is completed by the action of plants, which take in carbonic acid gas, use the carbon, and return most of the oxygen to the atmosphere. ”

“ We have said, that the substances which compose cast-iron, are iron, carbon, and oxygen, in a peculiar state of combination. We may also conclude, therefore, that, as carbon, by combustion in oxygen gas, or in atmospheric air, which contains about twenty-two per cent. produces carbonic acid, the carbon of the iron during its combustion, is changed, by its union with oxygen, into this acid. The products, then, are oxide of iron, and carbonic acid, the latter existing in the gaseous state. ”

“ These compounds, resolved into their elements by the processes of chemistry, yield a certain number (fifty-five) of substances which, under the conditions yet applied to them, are found to be incapable of further analysis, and are therefore called simple or elementary substances. They are singularly diversified in weight, mode of existence when separate, and relation to temperature and electricity.
In a free state under ordinary pressure and temperature, some (five) exist as gas; viz., hydrogen, oxygen, chlorine, fluorine, azote. Seven are non-metallic solids and liquids ”

“ Some gases are destitute of smell, as oxygen, azote and its protoxide, and carbonic acid; while others have a strong and characteristic odour, as ammoniacal gas. Some gases are very soluble in water, and others but slightly soluble, such as fluoric, fluosilicic, carbonic, sulphurous, and muriatic acids, and ammoniacal gas. Alkaline solutions absorb some gases, as nitrous, sulphurous, muriatic, fluoboric, carbonic, hydriodic, fluosilicic, chlorine, chlorocarbonic, and the two oxides of chlorine, sulphuretted hydrogen, telluretted hydrogen, and ammonia. ”

“ A few examples will be sufficient. By the combustion [xxv] of metals, iron for instance, we obtain a fixed product, and in the present case an oxide of iron; by the combustion of antimony and arsenic, the antimonic and arsenic acids; by the combustion of charcoal, we have carbonic acid gas, a gaseous product; by the combustion of potassium or sodium, we obtain a fixed alkali, depending however on the quantity of oxygen; by the combustion of sulphur, phosphorus, &c. acids; and when metals are burnt in chlorine gas, chlorides are produced. ”

“ Charcoal will not burn in dry chlorine. It unites with a less proportion of oxygen, and forms carbonic oxide gas, which burns with a deep blue flame. This combination is formed by distilling in a red heat, a mixture of equal parts of iron filings and chalk. This gas mixed with chlorine gas, and exposed to the sun's rays, will unite with it, and form chlorocarbonic acid gas. Carbon unites with azote, and forms cyanogen, the base of Prussic acid. ”

“ The causes of spontaneous combustion may be referred to chemical decomposition, and the change of quiescent into distributable heat. We remarked, that a mixture of chlorate of potassa and sugar is inflamed, when brought in contact with sulphuric acid; that, in the slaking of quicklime, the heat is sufficient to inflame oils; that pyrites by decomposition very frequently sets fire to combustible bodies; that oil of turpentine is inflamed by nitric acid; that pyrophorus, when exposed to the air, takes fire, and also phosphorus by slight friction ”

“ The action of a plant upon the air is therefore the separation of combustible material from that medium. Carbon is thus obtained from carbonic acid; from water, hydrogen. Plant life is chemically an operation of reduction, for in like manner ammonia is decomposed into its constituents, which are nitrogen and hydrogen; and sulphuric and phosphoric acids, which like ammonia, may have been brought into the plant through its roots in the form of salt bodies, are made to yield up the oxygen with which they had been combined, and their sulphur and phosphorus, combustible elements, are appropriated. ”

“ Nearly all the fluids, and solids also, used for procuring artificial light, such as naptha, various oils, tallow, wax, spermaceti, spirits of wine, ether, etc., are compounds of carbon and hydrogen in different proportions, with the occasional addition of some other elements, especially oxygen and hydrogen, in the proportions to form water; as a general rule, those bodies containing the greatest proportion of carbon give the most light, though not necessarily the most heat. ”

“ We may merely remark, that this effect is produced by the chemical union, which takes place between the sulphur and iron, forming a sulphuret of iron, analogous in composition to the native martial pyrites. The water is at the same time, decomposed, during which the mixture swells, becomes hot, and throws up the earth, producing at the same time a large quantity of sulphuretted hydrogen gas. ”

“ The elements which play important parts in organic compounds are carbon, hydrogen, nitrogen, chlorine, bromine, iodine, sulphur, phosphorus and oxygen. We shall here consider the qualitative and quantitative determination of these elements.
Qualitative.—Carbon is detected by the formation of carbon dioxide, which turns lime-water milky, and hydrogen by the formation of water, which condenses on the tube, when the substance is heated with copper oxide. Nitrogen may be detected by the evolution of ammonia when the substance is heated with soda-lime. ”

“ By the ordinary process we obtain sundry volatile [92] products, among which are pyroacetic acid and carburetted hydrogen gas.
When wood is carbonized in the usual manner, it yields from 16 to 17 parts of charcoal in the hundred; but when the operation is conducted in close vessels, the product is 28 per cent. a saving of eleven or twelve per cent. By this difference in the quantity, it appears that eleven or twelve per cent. is burnt in the common process. ”

“ The oxydation of carbon, for instance, in the fireplace, is the formation of the stable compound called carbon dioxide, and light and heat are evolved. The explosion of dynamite, again is the decomposition of an unstable compound. Hence, we begin to perceive that force-- the vital force-- which keeps the rabbit moving, is supplied by the decomposition and partial oxydation of compounds continued in its food, to carbon dioxide, water, urea, and smaller quantities of other substances. ”

“ The same odor is perceptible around stables and other places where animal matter is decomposing. All animal muscle, certain parts of plants, and other organized substances, consist of compounds containing nitrogen. When these compounds undergo combustion, or are in any manner decomposed, the nitrogen which they contain usually unites with hydrogen, and forms ammonia. In consequence of this the atmosphere always contains more or less of this gas, arising from the decay, etc., which is continually going on all over the world. ”

“ Some Dutch metal, or powdered antimony, or a bit of phosphorus, immediately takes fire when introduced into a bottle containing chlorine gas, forming a series of compounds termed chlorides, and demonstrating by the evolution of heat and light, the energetic character of chlorine, and that oxygen is not the only supporter of combustion; chlorine gas has even, in some cases, greater chemical power, because some time elapses before phosphorus will ignite in oxygen gas, whilst it takes fire directly when placed in a bottle of chlorine. ”

“ We know that all substances can be converted into gases, and that all gases can be reduced to liquids, and even solids, by the application of pressure and cold. If there is any way by which the visible substance of these fungi can be converted into its invisible gases, as water into oxygen and hydrogen, what we have seen can be logically explained. Perhaps, favoured by some affinity of the atmosphere, its constituent parts are broken up and become gases at this barometric pressure and temperature. We must ask the spirit, if he visits us again. ”

“ After separating the carbonic acid with lime water, that mixed gas contains in 100 measures, 20 of carburetted hydrogen; the rest being hydrogen and carbonic oxide, so that the gaseous mixture cannot be used for illumination. The best substances for furnishing a gas rich in luminifereous materials are, pitcoal, especially the cannel coal, resin, oil, fats of all kinds, tar, wax, &c. In some cases the gases evolved during the igneous decomposition of bones and other animal matters for the production of ammonia, may be employed for procuring light, but they are apt to emit a fetid odour. ”

“ The peculiar manner in which hydrogen gas appears to dissolve solid substances,—as iron, potassium, sodium, sulphur, phosphorus, selenium, and arsenic, may be explained by regarding the results as a manifestation of the powers of chemical affinity over the forms of bodies. In like manner, the solution of salt in water, or the mixture of alcohol in that fluid, may be viewed as chemical phenomena, although usually considered as simple cases of solution or mixture: alterations of temperature and other physical changes taking place in either. ”

“ An experiment to prove that the atmosphere does consist of nitrogen and oxygen, may be prettily proved in the following simple manner: A glass marmalade jar, or a soup-plate filled with water, and a piece of phosphorus as large as a pea, are the only things necessary. Take very great care not to touch the phosphorus, for the heat of the hand is sufficient to set it on fire, and a terrible wound would be caused. ”

“ Thus we learn that chalk is a body consisting of two compound molecules,—carbonic acid, which is formed by the combination of an atom of carbon with two atoms of oxygen,—and lime, which results from the union of an atom of calcium with one of oxygen.
The condition requisite to the production of chemical action between bodies is that they should be dissimilar. Two elementary atoms are placed within the spheres of each other’s influences, and a compound molecule results. Oxygen and hydrogen form water; oxygen and carbon give rise to carbonic acid; nitrogen and hydrogen unite to form ammonia ”

“ Moisture is evolved from substances containing water of crystallization or decomposed hydrates. If it possesses an alkaline or acid reaction, it must be tested in the first case for ammonia, and in the second case for a volatile acid, such as sulphuric, nitric, hydrochloric, &c.
62 Any evolved gas must be examined. 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. ”

“ Thus the agents which by their combination produced red precipitate, namely, the mercury and the gas, reappear as effects resulting from that precipitate when acted upon by heat. So, if we decompose water by means of iron filings, we produce two effects, rust and hydrogen. Now rust is already known, by experiments upon the component substances, to be an effect of the union of iron and oxygen: the iron we ourselves supplied, but the oxygen must have been produced from the water. ”

“ If we burn any vegetable substance it disappears, except a small quantity of earthy matter, which we call ashes. In this way we make an important division in the constituents of plants. One portion dissipates into the atmosphere, and the other remains as ashes.
That part which burns away during combustion is called organic matter; the ashes are called inorganic matter. The organic matter has become air, and hence we conclude that it was originally obtained from air. The inorganic matter has become earth, and was obtained from the soil. ”

“ Marble is a compound of carbonic acid and lime. The muriatic acid being the stronger of the two, takes the place of the carbonic acid, which escapes as a gas, the residue forming muriate of lime or chloride of calcium.
(18) Page 186. Lead pyrophorus is made by heating dry tartrate of lead in a glass tube (closed at one end, and drawn out to a fine point at the other) until no more vapours are evolved. The open end of the tube is then to be sealed before the blowpipe. When the tube is broken and the contents shaken out into the air, they burn with a red flash. ”

“ Is it not our habit to say that charcoal and sulphur and lead are bodies possessing potential chemical energy—that is, phlogiston; that, in the act of burning, their energy which was potential becomes kinetic or dynamical, and is dissipated in the form of light and heat; that the products of their burning (including the gaseous product now known to be furnished by the burning of charcoal) are substances devoid of chemical energy—that is, of phlogiston ”