Volatile organic compound

“ Animal substances, being composed nearly of the same elements with cruciferous plants, give the same products in distillation, with this difference, that, as they contain a greater quaintity of hydrogen and azote, they produce more oil and more ammoniac. I shall only produce one fact as a proof of the exactness with which this theory explains all the phenomena which occur during the distillation of animal substances, which is the rectification and total decomposition of volatile animal oil, commonly known by the name Dippel's oil. ”

“ Prepare stock solutions by adding known amounts of analytes to 10-mL volumetric flasks containing high purity solvent (carbon disulfide, methanol, toluene) . Solvents are chosen based on solubility for the analytes of interest and ability to be separated from the analytes when chromatographed. Highly volatile compounds should be dissolved in a less volatile solvent. For most compounds, carbon disulfide is a good general purpose solvent, although this will interfere with early eluting compounds. ”

“ For the extraction of aromatic substances from plants a number of bodies are used which possess great solvent power for essential oils, and are besides very volatile, or have a low boiling-point. These are particularly ether, chloroform, petroleum ether, and bisulphide of carbon. ”

“ Duhamel for this purpose is, that the fixed substances carried up by the Volatile Alkali of the Sal Ammoniac are actually volatilized; that they make, as it were, one whole with it; and are so closely combined therewith, that almost all the most efficacious means of separating fixed from volatile matters are unsuccessful with regard thereto. Nothing, for instance, is fitter to separate a volatile substance from a fixed one, than to mix the compound with a great quantity of water, and to distil the whole, with such a degree of heat as shall be exactly sufficient to elevate the volatile part. ”

“ Many volatile substances destroy the luminous appearance of phosphorus vapour, e.g., chlorine, hydric sulphide, sulphur dioxide, carbon disulphide, ether, alcohol, petroleum, turpentine, creasote, and most essential oils. On the other hand, bromine, hydrochloric acid, camphor, and carbonate of ammonia do not seem to interfere much with the phosphorescence. ”

“ The well-known pungent compound, ammonia, so exceedingly volatile at common temperatures, is converted into a crystalline, translucent, white substance at the temperature of -103°. The difficulties which necessarily attend the exposure of a body to extreme cold and great pressure at the same time, appear to be the only obstacle to the condensation of oxygen, hydrogen, and nitrogen gases. ”

“ If a fresh green leaf of tobacco be crushed between the fingers, it emits merely the herbaceous smell common to most plants; but if it be triturated in a mortar along with a very small quantity of quicklime or caustic alkali, it will immediately exhale the peculiar odour of manufactured tobacco. This arises from the active and volatile ingredients being liberated from their previous combination, by the ammonia developed by fermentation, or the action of a stronger base. ”

“ The nascent hydrogen which unites with the nascent nitrogen during the combustion is also derived from the organic matter which always contains enough carbon to decompose the water formed in order to be oxidized to carbon dioxid. While at first, therefore, during combustion, the hydrogen may unite with the oxygen, it becomes again free by the oxidation of the carbon and in this condition unites with the nascent nitrogen to form ammonia. ”

“ If the increased temperature to which the vegetable is exposed does not exceed the heat of boiling water, one part of the hydrogen combines with the oxygen, and forms water, the rest of the hydrogen combines with a part of the charcoal, and forms volatile oil, whilst the remainder of the charcoal, being set free from its combination with the other elements, remains fixed in the bottom of the distilling vessel. ”

“ The distillation is then started. It involves the formation of two sets of volatile products, namely— (1) combustible gases (including sulphuretted hydrogen and bisulphide of carbon vapour) , which must be led away to avoid nuisance and danger of fire, and (2) a very complex liquid or semi-liquid distillate. This latter is collected in successive fractions, generally in this manner:— (1) as "first runnings," what comes over at temperatures below 105° to 110°C.; (2) as "light oils," at temperatures between 110° and 210°C.; (3) as "carbolic oil," at temperatures between 210° to 240° C. ”

“ The chief difference between fixed or fat oils drawn from vegetables by expression, and volatile or essential oils, is, that the former contains an excess of charcoal, which is separated when the oils are heated above the degree of boiling water; whereas the volatile oils, containing a just proportion of these two constituent ingredients, are not liable to be decomposed by that heat, but, uniting with caloric into the gasseous state, pass over in distillation unchanged. ”

“ The loss of ammonia by volatilization will, under such circumstances, especially in the cold season of the year, be very trifling, and the rain which falls will only serve to incorporate the soluble matters with the soil, where they will be retained by its absorptive power. ”

“ Ammonia.—If the sal ammoniac of the shops be mixed with quicklime, a powerful odour is immediately perceived, and an invisible gas is given off which strongly affects the eyes. This gas is ammonia. Water dissolves or absorbs it in very large quantity, and this solution forms the common hartshorn of the shops. The white solid smelling-salts of the shops are a compound of ammonia with carbonic acid,—a solid formed by the union of two gases. ”

“ I think it may be laid down as a general rule, that extreme pulverization assists the operation of all substances whose active principles are not easily soluble, and of compound powders whose ingredients require, for their activity, an intermixture; whilst it certainly injures, if it does not destroy, the virtues of such as contain as their active constituent, a volatile principle which is easily dissipated, or extractive matter which is readily oxidized. ”

“ Animal matters yield in distillation, first, a phlegm, and then, on increasing the fire, a pretty clear oil, which gradually becomes thicker, blacker, more fetid, and empyreumatic. It is accompanied with a great deal of volatile alkali; and if the fire be raised and kept up till nothing more comes over, there will remain in the distilling vessel a coal like that of vegetables; except that when it is reduced to ashes, no fixed alkali, or at least very little, can be obtained from them, as from the ashes of vegetables. ”

“ Straw and all other kinds of vegetable matter undergo the putrid fermentation more rapidly when mixed with animal matter. Much heat is evolved during this process, and a variety of volatile products are disengaged, as carbonic acid and hydrogen gas, the latter of which is frequently either sulphurated or phosphorated.—When all these gases have been evolved, the fixed products, consisting of carbon, salts, potash, &c. form a kind of vegetable earth, which makes very fine manure, as it is composed of those elements which form the immediate materials of plants. ”

“ With regard to the chemical properties of petroleum, it is not necessary to say more in the present place than that the lighter and more volatile constituents, known commercially as naphtha and benzene, must be removed by distillation in order to leave a residue composed principally of hydrocarbons which, while containing the necessary carbon for combustion, shall be sufficiently free from volatile qualities to avoid premature ignition and consequent danger of explosion. ”

“ Be this as it may, it seems certain that by scrupulous return to the soil of all that comes out of it the resources of Nature are made increasingly available for the benefit of man.
When organic matter is mixed with water, a process of putrefaction and fermentation is started, and the organic matter, instead of undergoing oxidation, is reduced, and among the commoner products of this process are ammonia with sulphuretted hydrogen and marsh-gas, which are both combustible. ”

“ This atmosphere will contain no supporter of respiration; it consists of nitrogen, carbonic acid, and carbonic oxide, and some watery vapour, with a little sulphur and traces of other volatile impurities contained in the fuel. The carbonic oxide is a violent poison. The other gases named are all either inert, unable to support life, or positively noxious. They will penetrate under the pressure of 15 lb. ”

“ The air may be contaminated by the disengagement of poisonous gases, or by the propagation of miasms.
The decomposition of bodies in the earth is a real organic combination; its products are quite well known. The principal and most abundant of them is carbonic acid, a substance that is generated by the slow combustion of the carbon contained in all organic matter, vegetable or animal, whether it be a blade of grass, a leaf, wood, manure, or a dead body. ”

“ These gentlemen, starting at the beginning of the works where the croton water enters by five different mains, and followed the course of the water through each step of the process, whereby the water was filtered, then heated to destroy organic as well as to drive off decomposing and volatile organic matter as well as other impurities and the filtered water there distilled by the most practical and complete apparatus conceivable ”

“ Nichols, of Boston, show an average of only four tenths of one per cent of carbonic acid with mere traces of sulphureted hydrogen, marsh-gas, and ammonia. The putrid organic vapors, and the putrefactive germs, particles, and spores of fungi, were found also in extremely minute quantities. ”

“ It is a colourless or faintly-yellow acid liquid, the depth of colour depending on its purity, and especially its freedom from iron. The liquid is volatile, and can be separated from fixed matters and the less volatile acids by distillation; it has a strong attraction for water, and fumes when exposed to the air, from becoming saturated with aqueous vapour. If exposed to the vapour of ammonia, extremely dense clouds arise, due to the formation of the solid ammonium chloride. The acid, boiled with a small quantity of manganese binoxide, evolves chlorine. Dioxide of lead has a similar action ”

“ The hot gases from the furnace impart their heat to the liquor, causing the volatilization of the condensed gases, and at the same time act chemically upon the liquor and evolved gases, so that ammonia and sulphuric acid are resulting products, in the compound state of sulphate of ammonia. The formation of the ammonia produced in the process is probably due to the decomposition of nitrogenous bodies contained in solution in the liquor—the sulphocyanide, for instance; the nitrogen being given off in the form of ammonia. ”

“ When the water runs in small quantity, or is altogether stopped from neglect, the quantity of vegetable and animal deposit carelessly allowed to accumulate in these channels emits a profusion of gaseous volatile poison, more or less penetrating and pernicious, according to the season of the year and heat of the weather. ”

“ By dry distillation it yields inflammable gases, a small quantity of water, a little acetic acid, a volatile oil (OIL OF AMBER; O′LEUM SUC′CINI, L.) at first pale, afterwards brown, thick, and empyreumatic, and an acid (SUCCIN′IC ACID; ACIDUM SUCCIN′ICUM, L.) ; with residual charcoal 12 to 13%. Sp. gr. 1·065 to 1·09, but usually about 1·070. It cannot be fused without undergoing more or less chemical change. ”

“ 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. ”

“ To destroy organic matter the most powerful oxidizing agents are required. We must boil it with nitric acid and chloric acid and the most perfect chemical agents. To think to get rid of organic matter by exposure to the air for a short time is absurd. ”

“ The chemical agencies discussed were the following: sulphurous and sulphuric acids, discharged in vast quantities into the air of the city, by the combustion of coal and gas, the decomposition of street refuse and sewer gas, etc.; carbonic, nitric, and hydrochloric acids; carbolic, hippuric, and many other organic acids derived from smoke, street dust, sewer vapors, etc.; oxygen and ozone, ammonia, and sea salt.
The mechanical and physical agencies discussed were the following: frost; extreme variations in temperature, amounting in our climate to 120° F. in a year, and even 70° in a single day ”

“ The general method of procedure which has yielded the best results, is to remove the adsorbed hydrocarbons by various processes of combined oxidation and distillation, whereby the hydrocarbons of high boiling points are broken down into more volatile substances and removed at lower temperatures, or under conditions less likely to result in subsequent deposition of inactive carbon. Thin layers of charcoal and rapid gas currents are used so that contact between the volatilized hydrocarbons and the hot active charcoal may be as brief as possible. ”

“ When two bodies, of which one is more volatile than the other, or has more affinity to caloric, are submitted to distillation, our intention is to separate them from each other: The more volatile substance assumes the form of gas, and is afterwards condensed by refrigeration in proper vessels. In this case distillation, like evaporation, becomes a species of mechanical operation, which separates two substances from each other without decomposing or altering the nature of either. In evaporation, our only object is to preserve the fixed body, without paying any regard to the volatile matter ”