496 MJM. Buuseu and Scbischkoff's Chemical 



KO HO, and hence 0-0159 Mn^ O'* corresponds to 2-239 per 

 cent, of hydrate of potash. 



Now since sulphide of potassium in the determination with 

 oxide of copper passes into hydrate of potash, the quantity of 

 hydrate of potash equivalent to the sulphide of potassium, which 

 according to experiment (2) amounts to 1'077 percent., must be 

 subtracted from this 2"239 per cent. Hence there remains for 

 the hydrate of potash contained in the mixture 1'202 per cent., 

 which is equivalent to 1-0596 potash, or 2'2741 nitre. 



10. Determination of the Potash contained in the whole of the 

 constituents. — One measure of the liquid containing 1 grm. of 

 residue, gave, when evaporated with sulphuric acid and strongly 

 ignited, r0447 sulphate of potash, which corresponds to 56-497 

 per cent, of potash. 



Collating the results of these experiments, Ave get the follow- 

 ing as the composition of the residue : — 



I. 



Sulphate of potash .... 56-62 



Carbonate of potash .... 27-02 



Hyposulphite of potash . . . 7-57 



Sulphide of potassium . . . 1-06 



Hydrate of potash 1-26 



Sulphocyanide of potassium . . 0-86 



Nitrate of potash 5-19 



Charcoal. ....... 0-97 



Carbonate of ammonia . . . O'OO 



Trace of sulphur .... . O'OO 



100-55 



The quantity of potash contained in 100 parts of the residue 

 amounts thereibre, according to the analysis, to 56-88 per cent. 

 Bv direct experiment 56*50 per cent, was obtained, which diflfers 

 therefore only by 0-38 from the number calculated from the 

 analysis. 



It will be seen from this analysis, that the residue consists 

 chiefly of carbonate and sulphate of potash, and not, as is 

 assumed in the best artillery and technical works, of sulphide 

 of potassium, the quantity of which indeed scarcely exceeds 1 

 per cent. 



In order to answer the second question as to the composition 

 of the smoke, we collected and analysed the gray, porous, am- 

 moniacal deposit formed towards the open end of the long tube 

 ee,, which consists of condensed smoke. As this cannot be 

 removed from the tube without attracting moisture, it was im- 

 mediately dissolved in water, the suspended charcoal filtered off 

 and washed, and the filtrate well mixed and divided into eleven 



