2 Analysis of the residuum of fired gunpowder. [Jan. 



EXAMINATION AS TO QUALITY. 



4. — Submitted to the spirit-blow-pipe some portions of the 

 residuum, before mixing, burnt quietly on red hot charcoal 

 and fused without the smell of sulphur ; and some portions 

 appeared to deflagrate slightly. After being well mixed, 

 crepitation occurred on red hot charcoal before the common 

 blow-pipe, but no appearance of deflagration. 



5. - — A sample was dissolved in cold distilled water, filtered, 

 and a clear solution obtained. Sundry tests were applied, and 

 gave indications, as follows, viz : 



6. — Reddened litmus paper was immediately turned blue, 

 indicating the presence of alkali. 



7. — The three mineral acids occasioned effervescence, and 

 a precipitate : and a smell in one case like burning sulphur 

 in another like bilge water. Tartaric acid gave a precipitate 

 of supertartrate of potass or cream of tartar,— whence may be 

 inferred the presence of carbonic acid, of hydrogen, or sul- 

 phuretted hydrogen, and potassa. 



8. — Nitrate of baryta occasioned a dense white precipitate 

 of which a part was soluble and a part not soluble in dilute 

 acid. This test indicates the presence of sulphuric acid, and 

 the partial solubility of the precipitate, points out the presence 

 of carbonic acid. From the last applied tests and the pre- 

 sent test we may conclude that the solution contained sul- 

 phate of potassa and carbonate of potassa. 



9. — The sulphuric acid being removed by the baryta, the 

 clear solution afterwards obtained, was tested with nitrate of 

 silver, which gave a dense precipitate, changing quickly from 

 yellow through various shades to black. This indicates the 

 presence of sulphur, or of sulphuretted hydrogen. 



10. — A certain quantity of the residuum was dissolved in 

 distilled water filtered and then boiled; it gave off copious 

 fumes which smelt like bilge-water and which blackened sil- 

 ver. These fumes were sulphuretted hydrogen. The sul- 

 phuric and carbonic acids of this solution were then removed 

 by nitrate of baryta ; and nitrate of silver was afterwards ad- 

 ded and gave a dense precipitate, indicating that the solution 

 contained not only sulphuretted hydrogen, but also an hydro- 

 sulphuret 



