426 071 (he Action of the Acids 



state of powder. That consequently ammonia, the fixed alkalies 

 and lime, are the only substances mentioned in this course of 

 experiments which contain a metallic Ijasc. 

 I am, sir, 



Your obedient humble servant, 

 Broomfield, near 'J'auntun, ANDREW CrossE. 



Nov. 25, 1815. 



LXXIX. On the ylclion of Acids on the Sails j/si/nlli/ called 

 Hijptroxymuriates, and on the Gases produced J rom them. 

 By Sir Humphry Davy, LLJJ. F.R.S.* 



X. HE effects produced when concentrated hydro-sulj^huric Jicid 

 (oil of vitriol) is poured upon hyiieroxymuriatc of potassa, have 

 been often objects of chemical discussion ; the acid and the salt, 

 it is well known, become deep orange, and if any moisture is 

 present, or if heat is applied to the mixture, a detonation oc- 

 GUis. In a paper read before the Royal Society, I have ventured 

 to suppose that these phenomena depend uj3on the development 

 and sudden decomposition oC the compound of chlorine and oxy- 

 gen, which I have named euchlorine. 



A statement, which I understand has been made by M. Gay 

 Lussac, namely, that a peculiar acid, which he has called chloric 

 acid, may l)e piocured from the hyperoxymuriate of baryta by 

 sulphuric acid, led me to examine the action of acids on the hy- 

 peroxymuriates under new circumstances, and I have made some 

 observations which ajjpsar to me not unworthy of being- com- 

 nmnicated to the Royal Society. 



If 30 or 40 parts of sulphuric acid be poured upon one part 

 of dry hvperoxvmuriate of potassa in a wine-glass, and the salt 

 be agitated in the acid, there is a very slight effervescence only, 

 the acid becomes of a deep orange tint, and white fumes, mixed 

 with orange fumes, fill the upper part of the glass, which have 

 a very peculiar and not a disagreeable smell. 



The slight effervescence taking place in this process, induced 

 me to suppose that the substance which coloured the acid must 

 contain a larger proportion of oxygen than euchlorine; for I 

 have shown, in a work published in 18l2t, that hyperoxy- 

 muriate of potassa contains six proportions of oxygen ; and by 

 its decomposition 2-5 volumes of oxygen ought to be evolved for 

 every volume of chlorine ; and euchlorine procured from the 

 hyperoxynmriate of potassa by solution of muriatic acid, yields 

 only one volume of oxygen, and two volumes of chlorine. 



• From the Philosophicnl Transactions for 1815, part ii. 

 t Elcin. of Clicin. Pliil. 



1 on- 



