202 ARSENIATED HIDROGEN GAS. 



Phyjical Properties of Arfcniated flidrogen Gas. 



Its phyfical pro-r Arfeniated hidrogen is a permanent elafiic aeriform invlfible 

 jiejuea. fluid. It is a true chemical compound. Proufl aflerts that it 



depofits arfenic: This however I have never been able to ob- 

 ferve, if the gas were pure. It has an alliaceous fetid fmell. 

 It extinguiflies burning bodies. It is not abforbable by water; 

 but when this fluid is freed from atmofpheric air, it takes up a 

 fmall quantity of the gas which becomes difengaged again by 

 mere agitation. It dofes not change the colour of tindlure of 

 litmus. The fpecific gravity of arfeniated hidrogen is, at 28' 

 barometrical preflure = 0,5293, or, one cubic inch (old French 

 jTiCafure) weighs 0,2435 grains. It is therefore lighter than 

 oxigen, nitrogen, atmofpheric air, carbonic acid, nitrous gas, 

 ammonia, and gazeous oxide of carbon, but heavier than hi- 

 drogen and fulphurated hidrogen gales. It is abfolutely fata! 

 to Animal life. 



Cheniical Properties of Arfeniated Hidrogen Gas. 



Its chemical Arfeniated hidrogen, mingled with atmofpheric air, fuff©rs 



properties. |^q chemical change, but mere dilution. The fame holds good 



Mixed wjthni^ with refped to nitrogen. When njingled with nitrous gas, a 

 trous gast diminution of 0,02, or 0,03 takes place, which fometimes even 



amounts to 0,05. To afcertain the nature of this gas, I mixed 

 two parts of arfeniated hidrogen, with one of nitrous gas, and 

 gradually added oxigen, till no further diminution of bulk en-< 

 fued. On prefenting to this mixture a lighted taper, a loud 

 explofion took place, accompanied with flame. Probably part 

 of the oxigen added, remained uncombined; for a mixture of 

 two parts of nitrous gas, and three of arfeniated hidrogen, 

 could not be inflamed by the taper; arfeniated hidrogen is 

 mifceable with hidrogen, with carbonic acid, and with ammo- 

 nia in all proportions. 

 With oxiginized Into a cylinder half filled with arfenic and hidrogen, I fent 

 muriatic acid ^p bubbles of oxiginized muriatic acid gas. The bulk of the 

 gas was diminiflied, heat was evolved, and metallic arfenic 

 was depofited in a cryftalline ftate. On adding to the mixtare 

 an additional dofe of oxiginized muriatic acid gas, white fumes 

 appeared, and the depofited metal vaniflied. The fame ex;- 

 periment was repeated fucceffively, taking care to add no more 

 of the latter gas, than vvas juil fufficient to occafion the pre- 



cipitatiojD 



gas, 



