72 ON POTASSIUM AND 80.J>MTM. 



to bti^ a com. j^^^ insults from the decomposition of the potassium, 1 



pound of hi- ^ !•,,,> ,11, 



drogen aad an Cannot but think the facts prove absolutely the contrary, 



acidifying Rub- ^fjd that thev are suyporied by the experiment of the corn- 

 stance. 1 ^ c ' » r Jill 



bustion ot eqnai parts ot oximuruitic acid and hKlrogcii 



gasses, which <;ave muriatic acid for the result; the occu- 

 wtcy of which I can have no doubt of, although Mr. Daltoa 

 seems to hint, t,hat implicit reliance on that head is not to 

 be placed on it. INIr. Davy says it was attended with a 

 condensation of -rV or ^V ^^^ the vohirae, and the deposition 

 of a slight vapour ensued, which was always in smallest 

 quantity when tiie gasses were driest, Mr. Dalton says, 

 that he should have expected the coadensation to have 

 amounted to 4- or \- on the common hypothesis; by which 

 1 understand, that he still considers oximuriatic gas as a 

 compound of muriatic acid and oxigcn. Now viewing it in 

 this light, oximuriatic acid consists, according- to Chenevix, 

 of 77*5 muriatic acid \- 22*5 oxigea by weight. In the 

 combustion therefore of 1 00 measures of this gas, with an 

 equal quantity of hUlrogcn, the oxigen (reckoning itn spe- 

 cific gravity as 1 •I'io, atmospheric air bting 1*000) would 

 take (i0*48 measures of hidrogen, and a condensation of 

 00*72 would ensue, nearly lialf the whole quantity, and 

 vapour in considerable abundance would be the conse- 

 quence; but the slight portion mentioned by Mr, Davy 

 resulted from another cause, as proved by its quaniity dimi- 

 nishing, in proportion to the dryness and purity ©f the 

 gasses employed. , This immense difterence between the 

 condensation that does actually take pitice, and what ought 

 to occur, according to the common hypotliesis, is, I think, 

 an incontrovertible argument in favour of Mr. Davy's con- 

 clusion, that muriatic acid is composed of a base of hidro- 

 gen united to a peculiar body, a substance sui generis^ into 

 which not a particle of oxigen enters, however similar the 

 phenomena attending its union with many bodies may be 

 to tbi!>so produced b}' the combustion of inflammable sub- 

 stances in oxigen gas; since, as Mr. Davy justly remarks, 

 the evolution of light and heat are only to be regarded as 

 evidences of intense combination. With respect to tlie 

 oxigen of the hyperoximuriate of potash, as it is called, the 

 idea that it is furnifehed by 4he alkali seems to me to be 



t])p 



