I83G.] Analysis of the residuum of fired gunpowder. 5 



tions occurred as before mentioned (15). The saltpetre 

 was fused and weighed 59 grains. 



28. — The result of the analysis by biniary combination, is 

 therefore as follows : — ■ 



Sulphate of baryta .gr. 23.10 



Carbonate of do. ...... . 20.50 



Sulphuret of silver, ..... ,, 15.40 



Nitrate of potassa 59.00 



29. — And the several substances indicated by the vari- 

 ous tests are the following : — 



Sulphate of potassa (8) 



Carbonate of do (8) 



Sulphuretted hydrogen (10) 



Sulphuret of potassa (10) 



Uncombined alkali (a trace) (15) 



Charcoal and earthy matter (16) 



30. — We ought now from the foregoing biniary compounds 

 to make up the 50 grains of original matter experimented 

 on ; but before doing so it appears necessary to make a few 

 observations. 



31. — On the explosion of gunpowder one of the products 

 formed is sulphuret of potassium ; but it is difficult to as- 

 certain tho, real quantity, because the moment it dissolves 

 in water it is decomposed and forms new compounds, so 

 that the analysis has rather to do with these new compounds 

 than with the original ingredient. The following extract 

 from Henry's Chemistry, Vol. I. Ed. 1826, page 447, will 

 explain the matter more fully. 



32. — " The pure sulphnrets can exist, as such, only in the 

 ee dry state ; for the' moment they begin to dissolve in water, 

 (s a decomposition of that fluid commences ; sulphuretted 

 " hydrogen is formed ; and of this a part is disengaged, 

 " while another part, uniting with an additional proportion 

 <( of sulphur, composes bi-sulphuretted hydrogen. This 

 (( last, uniting with the base, forms an hydroguretted sul- 

 u phuret. At the same time, it has been stated by Ber- 

 (( thollet, sulphuric acid is composed, by the action of the 

 ** sulphur on the oxygen of the water. This however, Gay 

 6i Lussac has shown, takes place only when the sulphuret 



