Page:Proceedings of the Royal Society of London Vol 1.djvu/372

Rh 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 ahalf, making fourteen grains and a half of dry muriate of potash, of which 49.,ths must be acid, according to Berthollet's esti- mation, and consequently there are légtlls 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 maybe 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. \Vires 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.

\Vith 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 potasium, but the nitrogen was not decomposed. Nitrogen was next mixed with oxymnriatic acid, and passed through a red-hot tube, without effecting any de- composition.

Notwithstanding such a want of conformation by any new processes, the original grounds for supposing oxygen present in ammonia remain. The amalgam produced from ammonia, which yields ammonia again by apparent oxidation, might lead to the inference