the Combustion of Gun-cotton and Gunpowder. 275 









Vol. at 0°. 









and 1 metre 





Volume. 



Pressure. 



Temp. 



pressure. 



Original volume . . . 



113-26 



0-2729 



15-6 



28-8 



After addition of air . . 



183-36 



0-3494 



16-8 



60-36 



After addition of oxygen . 



204-32 



0-4295 



16-4 



71-79 



After explosion . . . , 



185-62 



0-3522 



15-4 



61-89 



After absorption of CO 2 . 



167-90 



0-3476 



15-1 



55-31 



After addition of H . . 



224-67 



0-4068 



16-2 



86-30 



After explosion .... 



166-38 



0-3355 



15-7 



52-79 



By applying the formulae of the gasometric methods already 

 mentioned in the analysis of gun-cotton, since the gases are 

 qualitatively the same, the values are obtained, for carbonic 

 oxide =5-21, hydrogen =3*03, marsh-gas =1-38, and nitro- 

 gen = 19-18. 



Hence the total gas calculated for 100 parts consisted of — 



42-74 vols. Carbonic acid 



0-86 

 10-19 





Sulphuretted hydrogen 

 Carbonic oxide 



2-70 



a 



Marsh-gas 



5-93 

 37-58 





Hydrogen 



Nitrogen 



100-00 



The determination of the solid residue in the mortar was 

 effected, after removing the gases, by digestion with water, which 

 was drawn off through a tap in the bottom and rapidly filtered. 



The results of the analyses were as follows : — 



1. Sulphide of Potassium. — The entire filtered liquid was 

 digested in three large boiling flasks with well-ignited oxide of 

 copper, thereupon filtered, and the residue dissolved in fuming 

 nitric acid. Treated with nitrate of baryta, it gave 0-1015 grm. 

 of sulphate of baryta, which corresponds to 0*0478 grm. sulphide 

 of potassium in the residue of 36-8366 grms. powder. 



The liquid filtered from the oxide of copper was made up to 

 6 litres for the sake of further investigation. 



2. Carbonic Acid. — A litre of this liquid gave with nitrate of 

 silver a precipitate of carbonate and sulphide of silver. Treated 

 with ammonia, the carbonate dissolved, and was separated from 

 sulphide by a weighed filter, and precipitated in the filtrate as 

 chloride of silver by means of hydrochloric acid. Its weight 

 amounted to 3-0475 grms., which corresponds to 0*4687 grm. 

 combined carbonic acid ; hence in the entire residue there were 

 2*8126 grms. combined carbonic acid. 



. As a control, the carbonic acid was determined by chloride of 



T2 



