﻿116 Canadian Record of Science. 



of heat, preside over the making of different chemical 

 compounds, and how the dormant heat can be made active 

 again when the compounds are excited to chemical change, 

 and liow each one is stamped as with a birth-mark by its 

 special heat value. 



This peculiar stamp set upon acetylene is at the same 

 time a token of valuable and also of dangerous qualities. 

 Heat is added to the heat of combustion and brings about 

 more sudden changes and places acetylene with the class 

 of bodies known as fulminates. These are distinguished 

 from explosives like gunpowder by their capability of 

 suddenly evolving stored-up heat, which causes a great 

 expansion of gaseous products. Berthelot has calculated 

 that fulminate of silver develops a pressure of 600,000 

 lbs to the square inch in the incredibly short time of one- 

 thirty-millionth of a second. The acetylide of silver has 

 similar properties, and the lightest shock suffices to ex- 

 plode it. It occurred to Berthelot to see whether acety- 

 lene gas might not decompose spontaneously into carbon 

 and hydrogen with explosive suddenness. We have seen 

 that it decomposes into these products, hut ivithout explo- 

 sion, when strongly lieated, and only in one way could it 

 be made to decompose explosively. Berthelot succeeded 

 in detonating pure acetylene by subjecting it to the shock 

 of fulminate of silver. 



The danger seems very slight that acetylide of copper 

 or some other metal may form in an acetylene gas holder, 

 and when exploded by friction or heat cause the whole 

 mass of gas or liquid acetylene to explode. The subject, 

 however, is worthy of further study. 



As vvas said in the beginning, the problems which are 

 suggested by this new industry touch on all sides upon 

 some of the most important of the recent discoveries in 

 chemistry and physics, and the ease with which acetylene 

 can be obtained opens the door to many new experiments. 

 Such questions, for instance, as the use of acetylene in 



