Page:Popular Science Monthly Volume 25.djvu/216

206. It has given the flavor to many a sherbet and many a confection.

Nitrobenzine is known in trade under the purely fanciful name of essence of mirbane, and is used by perfumers as a substitute for the oil of bitter-almonds—a substance which is also made artificially. It plays an important part in modern industry, because it is employed in the manufacture of aniline.

As the experiments in synthesis are continued, and more and more complicated bodies are evolved from the primitive hydrocarbon, the wealth of the field of researches open to the investigator becomes more and more surprising. How many combinations have already been effected, and how many thousand remain to be discovered! Benzine is only one of many hydrocarbons derived from coal-tar, and nitrobenzine is only one of the nitrogenized derivatives from it. There are also iodine, bromine, and chlorine derivatives, which may be obtained, not only by successive substitutions of those substances for one or more atoms of hydrogen, but also by additions of them, without displacing hydrogen. Sulpho-derivatives are also known, as well as nitrogenized derivatives of benzine chloride, iodide, and bromide. Instead of chlorine, iodine, and bromine, we may substitute organic radicals for hydrogen and get other new series. And these series of derivatives furnished by benzine are paralleled by other like series derived from toluene, xylene, and a hundred other hydrocarbons. Mathematicians exhibit a formidable total of the different possible arrangements according to which the units may be grouped by twos and threes, etc.; the seven notes of the musical scale are arranged in infinite variations; and chemistry disposes the seven or eight bodies occurring in organic matters in a similar endless diversity of combinations. If we are permitted to extend the comparison, we may say that as the musical arrangements are based upon a certain fundamental chord, so types of chemical arrangements center around a particular model, like benzine, to which it is easy to bring the whole series into relation.

Aniline exists already formed in coal-tar, but in very small quantity. Industry does not look after it, for the processes of extraction would be too costly. It is more convenient to make nitrobenzine and then reduce it, or deprive it of its oxygen by bringing it in contact with substances that will take that element from it. This may be effected by several processes. Sulphureted hydrogen, iron in fine particles, and acetic acid, are often employed as reducing agents. All the substances we have thus far derived from coal-tar are colorless. The moment has come for colors to appear. We have obtained aniline by deoxidizing nitrobenzine. If we are expecting in turn to recover nitrobenzine by oxidizing aniline, we shall find ourselves mistaken. We can, indeed, fix oxygen upon the hydrogen, but the hydrogen-atoms will separate during the process from the molecule of aniline.