on the Nature of certain Bodies. 409 



filled with oxymurlatic acid gas, which had been introduced 

 after exhaustion of the globe. They were preserved, for 

 nearly an hour, in intense ignition, by the same means that 

 had been employed in the experiment on nitrogen. At first, 

 white fumes arose, probably principally from the formatioa 

 of common muriatic acid gas, by the action of the hydro- 

 gen of the charcoal upon the oxymuriatic acid, and the 

 combination of the gas so produced, with aqueous vapour 

 in the globe ; but this effect soon ceased. At the end of 

 the process, the oxymuriatic acid gas was found unaltered 

 in its properties, and copper leaf burnt in it with a vivid 

 light. The charcoal did not perceptibly differ from the 

 charcoal that had been exposed to nitrogen. My view in 

 making this experiment, was to ascertain whether some 

 new combination of carbonaceous matter with oxygen 

 might not be formed in the process, and I hoped likewise 

 to be able to free charcoal entirely from combined hydrogen, 

 and from alkaline and earthy matter, supposing they ex- 

 isted in it, not fully combined with oxygen. That hydro- 

 gen must have separated in the experiment, it is not possible 

 to doubt ; and on evaporating the deposit on the sides of 

 the globe, which was in very minute quantity, and acted 

 like concentrated nuirialic acid, it left a perceptible saline 

 residuum*. 



IV. Further Inqjiiries respecting Muriatic Acid. 

 The experiments on muriatic acid, which I have already 

 had the honour of laying before the Society, show that 

 the ideas which had been formerly entertained respecting 

 the difference between the muriatic acid and the oxymu- 

 riatic acid are not correct. They prove that muriatic acid 

 gas is a compound of a substance, which as yet has never 

 been procured in an uncombined state, and from one-third 

 to one-fourth of water, and that oxymuriatic acid is com- 

 posed of the same substance (free from water) united to 

 oxygen. They likewise prove, that when bodies are oxi- 

 dated in muriatic acid gas, it is by a decomposition of the 

 water contained in that substance, and when they are oxi- 

 dated in oxymuriatic acid, it is by combination with the 

 oxygen in that body, and in both cases there is always a 

 union of the peculiar unknown substance, the dry murialio 

 acid with the oxidated body. 



• Charcoal, over which sulphur has been passed, as in the cxperimen's 

 page 407, as has been shown by M. A. Benhollet, contaius suliilnir, and 

 rtiis I find after being licated to whiteucss ; such cliarcoal is a conductor of 

 •lectrici! V. and does uot differ in its external propprti':! froai common cliai- 

 ':r,A. 



Of 



