g^^ On the cnnjfihient Parts of Azof. 



vapour w'uhout the leaft particle of gas except the air Con- 

 tainecl ill the retort. After you have afcertained in this man- 

 ner that the water is not changed into gas in thefe tubes, to 

 prevent the objeAions of thofe who imagine that the external 

 ■Vir pafles through the tubes, fill one of them with fihngs of 

 %\n and put ^t into the fire, which you rnuft take care to keep 

 yp, Tl^pn make the fleam of water to pafs through it, Ir^ 

 the pneumatic apparatus yoq will obt?iin azotic gas mixed 

 with oxygen gas. The tin is changed into an oxyd. This 

 experiment, which was made by M. Von Hauch, may be 

 eafily pxplfiined fronri my principles. The tin takes from the 

 water only a pact of the oxygen it contains j the feft rein<iius 

 in union with the hydrogen, and forms azot. 



%. By tranfmitting the fteam of water over lead, in the 

 fame manner as in the preceding experiment, you will ob- 

 tziluj according to M, Von Hauch, the fame refult. At the 

 commencement of the operation the oxyd of the lead paflTes 

 \inder the bell with the gas and the fteam of the water, and 

 th§ mptal then appears under the form of a very fine powder. 

 The azotic gas obtained is in proportion to the oxygen gas 

 ^Imoft as 64 to 36, 



3. By tfanfmitting, in the fame manner, the fteam of 

 water through a tube filled with antimony, you obtain a 

 inixture of azotic gas and oxygen gas. There will be 89 parts 

 ©f the former, and t i of the latter. 



4, A porcelain tube was filled with black oxyd of man- 

 ganefp, and the tube expofcd to a very ftrong heat for n;iore 

 than two hours, until the oxyd had entirely ceafed to furnifh 

 ©xygen gas. The fteam, of water wa^ then made tp pafs over 

 this oxyd deprived of the greater part of its oxygen. At firft^ 

 exvgen gas pretty pur€ was obtained, and then azotic gas. 

 This experiment of M. Von Hauch is very inftru6live. The 

 manganefe evidently abforbed, firft the hydrogeUi 3^'^ the^ 

 a part of the oxygen of the water. 



^, The fteam of water was made to pafs through the fame 

 tube, filled with the fame mangancfe xyhich h^d ferved for 

 the fourth experiment. Azotic gas was obtained; and the 

 tire being continued for three hours, the difenjragement of 

 ^he a?ot«c ga^ continued as; long as tlii; fteam of the water 



