SCHULTZE'S POWDER. 459 



8. The Faversham " Cotton Powder " consists of a mixture of 

 equal weights of gun-cotton and barium nitrate. Gun-cotton 

 may also be mixed with sodium nitrate, the hygroscopic pro- 

 perties of which lessen the risk of inflammation. But special 

 detonators must then be employed. The relations by weight of 

 total combustion would be 51'6 of gun-cotton to 484 of barium 

 nitrate. The heat liberated is practically the same (pp. 4 

 and 134) as for an equivalent weight of potassium nitrate ; but 

 the barium nitrate mixture weighs 2223 grms. instead of 1971 

 grms., or one-eighth more. 



The volume of the gases gives rise to the same relations, this 

 volume being identical for equivalent weights (provided only 

 the carbonate be neutral), but less at equal weights. 



9. Schultze's powder, made from nitrated wood meal, will now 

 be considered. 



It is prepared from wood reduced to small grains, which are 

 freed from resinous, nitrogenous, and incrusting matters by the 

 following treatments. It is boiled for six to eight hours with 

 sodium carbonate; washed, dried, and treated successively by 

 steam, cold water, bleaching powder ; then 16 parts of a mixture 

 of nitric acid of 1*50 specific gravity, with twice its volume of 

 concentrated sulphuric acid, is allowed to react for from two to 

 three hours. In this way is obtained a substance nearly related 

 by its composition to heptanitrocellulose 



In reality it is a mixture of several unequally nitrified products. 

 It is washed in cold water, then in a weak solution of sodium 

 carbonate. This done, the substance is steeped in a concentrated 

 solution of potassium or barium nitrate, pure or mixed, and 

 dried at 45. The nitrate and the ligneous grains, which are 

 impregnated beforehand with 20 to 25 per cent, of water, can 

 again be incorporated under light edge runners. The com- 

 position of the final substance varies with the amount of the 

 nitrates. The following is the result of some of the analyses : 

 Nitrocellulose soluble in alcohol ether 13-1 \ KQ ^ 

 insoluble 44-9 / 



Foreign matters soluble in alcohol 2-3 



Potassium nitrate 6-2 



Barium nitrate 30-0 



Water 3-5 



100-0 

 Another sample 



Nitrocellulose .. ... ... ... ... 66*5 



Barium nitrate 15-0 



Potassium nitrate 15-0 



Water 3-5 



100-0 

 1 One grm. produces 166 cc. of nitric oxide by Schlcessing's process. 



