1 56 Scientific Intelligence. — Medical Chemistry. 



and silver. When the fulminathig silver is placed under dilute sul- 

 phuric acid, nitrogen is disengaged, but the greater part is transform- 

 ed into sulphate of silver and sulphate of ammonia. But the dis- 

 engagement of nitrogen cannot proceed from the decomposition of 

 ammonia, under the influence of this acid. — Ibid. 



23. Percussion powder. — Gunpowder made of chlorate of potash, 

 sulphur and charcoal is much stronger than that made of saltpetre. 

 Welter filled small bombs with this powder, buried them in the 

 ground, and then caused them to explode. They were constantly 

 broken into pieces of the size of a horse chesuut, while those explod- 

 ed with common gunpowder, under circumstances precisely similar, 

 were broken into much larger pieces. As a material for priming to 

 be fired by percussion or otherwise, this powder has serious in- 

 conveniences. It soils and corrodes the lock very rapidly, a de- 

 fect which cannot be easily remedied, and the use of it is very much 

 abandoned. 



A preference is therefore given to a powder composed of ten parts 

 of fulminating mercury and six of common priming powder. The 

 fulminate is ground upon a marble slab with a wooden muUer after 

 having been moistened with thirty per cent of water ', six parts of 

 common powder are then added, and the grinding continued. A 

 firm paste is thus attained, which being properly dried, is divided into 

 grains, one of which is sufficient for a priming. — tdnri: de Chimie^ 

 Sept. 1829. 



MEDICAL CHEMISTRY. 



1 . Decomposition of sulphates- in waters, by organic substances. — 

 M. Vogel has made some direct experiments on this subject and has 

 found that a very weak solution of sulphate of soda, and a saturated 

 solution of sulphate of lime, mixed with sugar, w^ith gum arable, with 

 liquorice, or with an infusion of woad, and kept a long time in pitch- 

 ers, sheltered from the light, were decomposed ; that sulphuretted 

 hydrogen, carbonic acid, and acetic acid were formed ; that the 

 mixture acquired a strong smell, and when heated to ebullition, emit- 

 ted sulphuretted hydrogen and carbonic acid. 



This observation may explain the formation of a great number of 

 hepatic waters. M. Dumenil had before observed acid in some 

 mineral waters, and M. Vogel has confirmed this observation. — Idem. 



