Theory of Gunpowder. 491 



which, when treated with bisulphide of carbon, gave 0-1080 grm. 

 of charcoal free from sulphur. 



1-1285 grni. gave 02380 of the same residue, which, by oxi- 

 dation with chlorate of potash and precipitation by chloride of 

 barium, gave 0-8028 grm. sulphate of baryta. 



0-1844 grm. of the charcoal free from sulphur, gave 0-0606 

 grm. water and 0-4658 grm. cai'bouic acid. 



The powder consisted therefore of 



Nitre 78-99 



Sulphur 9-84 



rCarbon 7-69 



CharcoalJ hydrogen 0-41 



l^narcoal^ Oxygen 3-07 



^Traces of ash . . . . 000 

 100-00 



In order to ascertain the qualitative composition of the solid 

 as well as the gaseous products of the explosion of powder, we 

 used the small apparatus, Plate III. fig. 1. rt is a brass tube 

 250 millims. long and 2 millims. wide, fitting air-tight into the 

 cork b, and in which the finely pulverized gunpowder is pressed 

 down. This tube a, as soon as the powder is inflamed and issues 

 from the open extremity with uniform hissing flame, is fixed air- 

 tight in the wide glass tube d, by means of the cork b. The tube 

 d is thereby heated so rapidly that it readily cracks at the place 

 at which the flame touches it. To prevent this, a sieve-shaped, 

 perforated tin tube, or a tube of thin glass, is so inserted as to 

 protect the tube d from the direct action of the flame. 



The residue and smoke of the exploded powder remain in the 

 tubes a and d, while the gases issue from the delivery tube, and 

 may be collected over mercury after the atmospheric air has been 

 displaced. 



The following substances may be readily detected in the solid 

 residue obtained in this apparatus : — 1, sulphate of potash ; 

 2, carbonate of potash ; 3, hyposulphite of potash ; 4, sulphide 

 of potassium ; 5, hydrate of potash ; 6, sulphocyanide of potas- 

 sium ; 7, nitrate of potash ; 8, carbon^ 9, sulphur; 10, carbon- 

 ate of ammonia. The gaseous products of decomposition con- 

 tain, on the other hand, — 1, nitrogen; 2, carbonic acid; 3, car- 

 bonic oxide ; 4, hydrogen ; 5, sulphuretted hydrogen, and occa- 

 sionally considerable quantities of (6) binoxide of nitrogen, and 

 even protoxide of nitrogen. 



To prcjjare the material for the quantitative determination of 

 these substances, we have made use of another apparatus which 

 is represented in fig. 2 : a is a vulcanized india-rubber tube 

 filled with about 15 to 20 grms. powder, and fitting on the brass 



2 K2 



