430 NITRIC ETHERS PROPERLY SO CALLED. 



But the new theory of the authors would tend to reduce it to 

 the half (p. 23). 



But this pressure is so quickly developed that the piston of 

 the crusher is often broken, which shows the shattering charac- 

 ter of nitromannite. The same property intervenes in the tests 

 founded on the capacity of chambers hollowed in leaden blocks 

 by various explosives (p. 374). Now, the capacity hollowed by 

 a given weight of nitromannite is greater by a fourth (43 c.c. 

 for 1 grm.) than that hollowed by nitroglycerin (35 c.c. for 

 1 grm.) Nitromannite, moreover, manifests a much more 

 marked tendency to tear the leaden blocks in diagonal direc- 

 tions. These facts contrast with the theoretical calculation of 

 the pressures or of the maximum work, which give nearly the 

 same value for nitromannite and nitroglycerin. They show 

 that the empirical method of chambers hollowed by an explo- 

 sive does not really measure either the pressure or the work, 

 but certain more complicated effects. 



