SYNTHETIC ORGANIC PRODUCTS 485 



latter substance, the chemical name of which is dichlordiethyl 

 sulphide, may be regarded as diethylether (p. 348) in which oxy- 

 gen is replaced by sulphur and two hydrogen atoms are replaced 

 by chlorine. It was produced by the action of ethylene C2H4 

 upon sulphur monochloride S 2 C1 2 . 



Both of the above substances are actually toxic, that is, a 

 sufficient concentration will induce death. Many other sub- 

 stances were used, however, which merely put the victim tempo- 

 rarily out of action. Among these were lachrymatories (tear- 

 producing substances) such as benzyl bromide C 6 H 5 .CH 2 Br, and 

 sternutatories (sneeze-producing substances) such as diphenyl- 

 chlorarsine (CeHs^AsCl. The latter substance is a derivative 

 of arsine AsH 3 , the three hydrogen atoms being replaced by two 

 phenyl groups C 6 H 5 and one chlorine. Mustard gas in very low 

 concentration also acted as a skin irritant. 



The methods employed for obtaining protection against toxic 

 gases have already been discussed (p. 421). 



Exercises. 1. Write graphic formulae (see Chapter XXIX) 

 for the following synthetic essences: ethyl formate, ethyl 

 butyrate, benzaldehyde, diphenyl ether. 



2. What chemical change would occur after mixing nitro- 

 glycerine with sodium hydroxide solution? Name the kind of 

 reaction and give the equation. 



3. When nitroglycerine explodes, in what relative volumes are 

 steam, carbon dioxide, and nitrogen produced? What principle 

 is used in answering this question? 



4. Make an equation for the decomposition of guncotton, 

 similar to that given for nitroglycerine (p. 482). 



5. Make an equation for the denitration of guncotton by an 

 alkali. 



6. Write the graphic formulae for the following substances: 

 acetic anhydride, trinitrotoluene, picric acid, phosgene, chlor- 

 picrin, mustard gas, benzyl bromide, diphenylchlorarsine. 



