ANTISEPTIC AND ANTIPYRETIC 395 



of molecules of the same or of different members of the 

 group ; two benzene molecules form naphthalene (C 10 H 8 ) ; 

 a benzene and pyridine molecule quinoline (C 9 H 7 N), which 

 is allied to quinine ; indeed, it is generally believed that 

 many of the organic alkaloids are closely related to this 

 aromatic series. The higher members appear to be the 

 most active. Rearrangement of the atoms of these bodies, 

 and substitution of various radicles, will doubtless produce 

 other valuable substances. 



The lower members of the series are the most useful 

 medicinally. They are antiseptic, usually antipyretic, fre- 

 quently analgesic. They affect the central nervous system 

 in a characteristic manner, at first, and in moderate doses, 

 causing great irritability, with tremors, convulsions, and 

 paralysis. Later, there is great depression of the medul- 

 lary centres causing marked muscular weakness, paralysis, 

 and collapse. They exhibit a marked contrast to the lower 

 members of the fatty or marsh-gas series (CH 4 ), which 

 chiefly affect the higher cerebral nerve centres, are at 

 first indirect stimulants by removal of inhibition, and later 

 anaesthetics. 



BENZOL or BENZENE, a mixture of homologous hydro- 

 carbons, obtained from light coal tar oil. It contains about 

 70 percent, of benzene, C 6 H 6 , and 20 to 30 percent, of toluene, 

 C 6 H 3 CH 3 . It is an ethereal, inflammable liquid, with an 

 acrid and bitter taste, the odour of coal-gas, and the 

 specific gravity *888. It is insoluble in water, soluble 

 in alcohol and ether, and a useful solvent for sulphur, 

 phosphorus, chlorine, iodine, many alkaloids, fats, resins, 

 and caoutchouc. Benzene is a perfectly distinct body from 

 benzin, petroleum benzin, or petroleum ether, which is a 

 purified distillate obtained from American petroleum a 

 paraffin of the marsh-gas series, consisting chiefly of 

 C 5 H 12 , and sometimes used as an anaesthetic, anthelmintic, 

 and parasiticide. 



Benzol or coal-tar benzene is irritant, antiseptic, and 

 parasiticide. Its irritant effects are especially notable on 

 mucous and skin-abraded surfaces, or when applied with 

 friction. Moderate doses, when swallowed, produce saliva- 

 tion, slight temporary pyrexia, and obstinate constipation. 



