352 



of potash in such state, as is allowed to be perfectly dry, according 

 to the latest experiments of the most celebrated chemists, Mr. Davy 

 converted eight grains of potassium into muriate of potash, by burn- 

 ing it in muriatic acid gas. Now, according to the experiments of 

 Berthollet, recently published, eight grains of potash would make just 

 twelve grains of muriate of potash, by the addition of four grains of 

 acid. But the eight grains of potassium received an increase of six 

 grains and a half, making fourteen grains and a half of dry muriate of 

 potash, of which 4-rVths must be acid, according to Berthollet's esti- 

 mation, and consequently there are lAths of oxygen added to the 

 potassium instead of hydrogen being extricated from it. 



The endeavours of the author were next directed to obtaining 

 more direct evidence of the composition or decomposition of nitro- 

 gen than he had hitherto done ; and though his results have been 

 mostly negative, he details a number of laborious and minute expe- 

 riments, which he conceives may be of importance in settling various 

 questions of doctrine that have been agitated. 



Since nitrogen has been supposed to be produced during the de- 

 composition of water by electricity, Mr. Davy has repeated that ex- 

 periment by means of the powerful battery of the Royal Institution, 

 kept in continual action for nearly two months, the product of gas 

 being exploded about 340 times during the experiment ; but the to- 

 tal quantity of permanent gas which remained, was not quite one 

 quarter of a cubic inch, and this residuum was hydrogen, which 

 may easily be referred to a slight oxidation of the wires of communi- 

 cation. 



Other attempts were also made to form nitrogen or nitric acid 

 from pure water, but all were unsuccessful. Wires of platina were 

 fused by voltaic electricity in oxygen gas, saturated with moisture ; 

 with the hope, that at so high a temperature the water might combine 

 with more oxygen ; but this did not occur. 



The vapour of water was passed over red-hot manganese, but no 

 acid could thus be obtained, except by employing an unglazed 

 porcelain tube, which was permeable to atmospheric air. 



Since the formation of ammonia from pyrophori in various sub- 

 stances, appeared to indicate a formation of nitrogen, many such cases 

 were examined ; but it was found that the production of ammonia 

 always depended upon the previous absorption of nitrogen by the 

 charcoal present in such pyrophori. 



With a view to decompose nitrogen, potassium was intensely 

 heated in that gas by voltaic electricity, but without success. Phos- 

 phuret of lime was next substituted for potassium, but the nitrogen 

 was not decomposed. Nitrogen was next mixed with oxymuriatic 

 acid, and passed through a red-hot tube, without effecting any de- 

 composition. 



Notwithstanding such a want of conformation by any new pro- 

 cesses, the original grounds for supposing oxygen present in ammo- 

 nia remain. The amalgam produced from ammonia, which yields 

 ammonia again by apparent oxidation, might lead to the inference 



