t^o On the Compofition of AzoU. 



with the gas, and tlie watery vapours ; after which the metal itfelf appears in the form of 

 an extremely fine powder. The proportion of azote gas to that of the oxigen obtained is 

 as 64 to 36. 



3. When the vapours of water are paffed in the fame manner through a tube filled with 

 antimony, a mixture of azote and oxigen gas is obtained, in the proportion of 89 parts of 

 the former to 1 1 of the latter. 



4. A porcelain tube was filled with the black oxide of manganefe. The tube was ex- 

 pofed to a very ftrong fire for two hours, till the oxide had intirely ceafed to afford oxigen 

 gas. The vapours of water were then paffed over this oxide thus deprived of the greater 

 part of its oxigen. Another produdt of oxigen gas of confiderable purity, was firft ob- 

 taiined, and afterwards azote gas. 



This experiment of Mr. Van Hauch is very inftruQive. The manganefe firft abforbod 

 the hydrogen with aviditj', and afterwards part of the oxigen of the water. 



5. Through the fame tube filled with the fame manganefe, as had ferved for experiment 4, » 

 the vapours of water were paffed. Azote gas was obtained. The fire was kept up for 

 near three hours, and the difengagement of azote continued as long as the vapours were 

 paffed through. It ceafed when thefe vapours were flopped, but the difengagement of 

 azote began again as foon as the water was again made to boil, and the vapours began to 

 pafs over the manganefe. This experiment was repeated for fix following days during 

 three hours each day, and always with the fame fuccefs. When the operation was ended, 

 the manganefe was found adhering to the porcelain, fo that it could not be feparated. 



6. Dr. Pearfon, in his analyfis of water by the eleftric fpark always obtained azote gas, 

 befides the two gafes which compofe water. 



7. The fame Dr. Pearfon, by burning a mixture of oxigen and hydrogen gafes in a tube 

 hermetically clofed, obtained water and azote gas. 



8. Dr. Prieftley obferved, that oxigen gas, which remains for a time in contadi with the 

 pureft diftilled water, becomes partly changed into azote. I verified this obfervation, and 

 found as much as 0,1 of azote gas in the oxigen gas. 



9. A mixture of hydrogen gas and nitrous gas, which remains for a time in conta£t 

 with wat€r, no longer bums, but is found to be changed into atmofpheric air. I explain 

 this fadt by fuppofing, that the hydrogen has combined with part of the oxigen of the 

 nitrous gas, or of the water, and has become changed into azote gas. This experiment, 

 however, which was made by Mr. Link, did not fuccecd with me 



10. Dr. Prieftley found that hydrogen gas, which he had kept for a long time in contaft 

 with water, was intirely changed into azote gas. This experiment does not always fuc- 

 cecd. It fucceedcd four times with Prieftley. It is no doubt neceffary that the water 

 (hould contain oxigen gas. 



11. By burning together a mixture of eleven cubic inches of hydrogen gas, and one 

 cubic inch of oxigen gas, azote gas is obtained. This experiment of Mr. Yelin did not 

 fucceed with me. 



■ 12. Wheo 



