NITEOGEN BODIES OF MODERN CHEMISTRY. 213 



These are bodies less explosive, certainly, tlian gun-cotton, but wliich 

 belong" to the same class, carbo-bydrogeus, in which the hydrogen is re- 

 placed by uitryl. 



There are still other and very difterent nitrogen compounds, and, in- 

 deed, the first known, the oldest, belongs to a different cha[)ter. This 

 compound comes from phenyl acid, a radical which in many respects 

 excites the interest of chemists. The main source of i)henyl is benzol, 



""Ce 'He, or 



Fig. 10. 



CXXXDCCCOQCpOOOO 



ooocccococococo 



Pare benzol is a colorless liquid, somewhat refractive, as evaporable 

 as ether, of penetrating odor, but not unpleasant when much diluted. 

 It is the well-known scouring drops. This most volatile of the coal-oils, 

 called, eupion, is an exceedingly mobile and refractive medium, possess- 

 ing the i^roperty of dissolving all oily substances without aiiecting any 

 color or injuring any material; it can therefore be used to extract spots 

 of grease and oil from all fabrics, even from the most delicate rose- 

 colored silk. Spots from acids, fruits, or lye are not removed by it. 

 It produces no "effect whatever on discolored spots; it can merely 

 remove the grease and with that the dust; for every spot of grease on 

 a garment is naturally a place on which the dust floating in the air 

 is deposited. This benzine or benzol is, in a scientific view, phenyl- 

 hydrogen. 



By replacing the hydrogen with hydroxyl, HO, we obtain from ben- 

 zine carbolic acid, or phenyl acid, which in a pure state forms colorless 

 crystals, but, however carefully protected from the air, it changes grad- 

 ually to dull red, and finally to brown. Carbolic or phenyl acid is 

 found in coal-tar, and is obtained from it in the form of carbolate of 

 lime. The carbolate of natron, prepared by precipitating this salt of 

 lime by means of a natron lye, is of inestimable value to the physicians 

 as a means of obviating the fatal effects of hospital gangrene, of cleans- 

 ing wounds, and exciting healthy action which has been suspended. 



By substituting for oneatomof the hydrogenin benzine — nothydroxyl, 

 but nitryl — we obtain a new substance, nitrobenzol, mirbauol, and this 

 brings us to ordinary perfumery. Thus, from the benzol of coal-tar is 

 produced the artificial oil of bitter almonds, employed as a perfume in 

 common pomades, in many cleaning mixtures, and substances contain- 

 ing strongly-scented mineral matter, and in common soaps. This mir- 

 bauol is obtained by mixing carefully, drop by drop, at a low temi^era- 

 ture, benzol and nitric acid. It would be unsafe to mix at once the 

 whole mass of benzol and nitric acid, since it would produce intense 

 heat and lead to explosion. In mingling benzol and red fuming nitric 

 acid there is need of the greatest foresight, carefulness, and subdivision 

 of the process. In spite of refrigeration, the benzol dissolving in the 



