2o6 THE POPULAR SCIENCE MONTHLY, 



berry. It has given the flavor to many a sherbet and many a confec- 

 tion. 



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 modem 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 nitroben- 

 zine 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 dis- 

 placing hydrogen. Sulpho-derivatives are also known, as well as ni- 

 trogenized derivatives of benzine chloride, iodide, and bromide. In- 

 stead 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 ar- 

 rangements according to which the units may be grouped by twos and 

 threes, etc. ; the seven notes of the musical scale are arranged in in- 

 finite variations ; and chemistry disposes the seven or eight bodies 

 occurring in organic matters in a similar endless diversity of combina- 

 tions. 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 quan- 

 tity. 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 par- 

 ticles, 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. 



