2Q4. ARSENIATED HIDROGEN «AS. 



when a fmall quantity of arfeniated hidrogen is made to aft 

 upon a large quantit)' of oxiginized muriatic acid gas, part of 

 the oxigen of the oxiginized muriatic acid gas combines, not 

 only with the hidrogen of the arfeniated gas, and forms water, 

 but the metallic arfenic alfo becomes oxidifed. Reafoning from 

 this faft, we (hould be inclined to believe, that a mutual de- 

 compofition of both the gafes could be thus effected; but this 

 cannot be accomplidied; a diminution of bulk indeed takes 

 plsfce to a certain extent, but the complete difappearance of 

 both the gafes cannot be effefted. If the admixture of arfe- 

 niated hidrogen, with this oxiginized muriatic acid gas, be 

 continued no longer than white clouds appear, and the refidue 

 be then examined, it will be found to confift of hidrogen and 

 oxiginized muriatic acid gafes; and the mixture detonates at 

 the approach of a taper. The oxiginized muriatic acid gas 

 can only be feparated with difficulty by long agitation, in con- 

 tad with water, and It feeras as If it were become lefs foluble 

 in that fluid. If the feparatlon of this gas be accompliflied, 

 the remaining arfeniated hidrogen burns with a pure 'flame, 

 void of alliaceous odour, and contains no veftige of arfenic, as 

 Ihall be proved hereafter. From what has been ffated, the 

 following theory may be formed. 

 Th of the Arfenic, in combination with a certain portion of hidrogen, 

 decompofition of conflitutes arfeniated hidrogen gas. On prefenting to this 

 ^f«"'*'^^ '"'^'^"combination oxiginized muriatic acid gas, the oxigen of this 

 gen gai. ^^^ combines with the hidrogen, which held Ii^ folutlon the 



arfenic, and the latter is feparated. If more oxiginized mu- 

 riatic acid be added than is neceffary for this purpofe, the por- 

 tion of oxiginized muriatic acid gas does not ad further upon 

 the hidrogen, but merely upon the arfenic, and the latter be- 

 comes oxidifed. 

 Arfeniated hi- Hidrogen and arfeniated hidrogen may be mingled without 

 diogengas mix- jg^Q^pQg,^g g^ch other; the decompo.ltion can only be ef- 

 cd with hidro ^^^^^ ^^ ^^^^ contaa of fire; but if we mingle hidrogen, hold- 

 ing in folutlon fulphur and oxiginized muriatic acid gas, the 

 decompofition and foruiation of water is inftantly effedted. 

 This is likewife the cafe with arfeniated hidrogen gas. 

 Hidrogen com- Hitheno no combination of hidrogen with a metallic fubftance 

 bined with me. ^as been known; but it is highly probable, that fuch combina- 

 tallic fubftances. ^.^^^^ ^^^. ^^.^_ ^^.^ .^^^^^^ ^^^^^ ^^^ ^^ ^j^^ ^^^^ -^ ^^^ ^^^^ 



mation of this gas on which we are treating. If this be ad- 

 4 Hiitted, 



