352 Researches on the muriatic Acid 



waked by it, and waked with the idea of a cannon fired close 

 to them. 



The watchmen in the streets, and the toll-man at Hyde- 

 park corner, described the air as completely on fire, and the 

 tremendous sound as being quite close to them. Jt is not 

 improbable that the discharge, whether to or from the cloud, 

 took place in several points at once. If the account in the 

 papers of a sentinel being struck down, near the Horse- 

 Guards, was true, this must have been the case, and will 

 account for the explosion having been so violent in London. 

 I am, sir, 



Your obedient servant, 



Tilney-street, Nov. 7, 1810. H. C. EnGLEFIELD. 



LXV. Researches on the oxymuriatic Acid, its Nature and 

 Combinations; and on the Elements of the muriatic Acid. 

 With some Experiments on Sulphur and Phosphorus, 

 made in the Laboratory of' the Roi/al Institution*. By 

 H. Davy, Esq. Sec. R.S. Prof. Chem. R.L F.R.S.E.f 



JL he illustrious discoverer of the oxymuriatic acid consi- 

 dered it as muriatic acid freed from hydrogen %, and the 

 common muriatic acid as a compound of hydrogen and 

 oxymuriatic acid; and on this theory he denominated oxy- 

 muriatic acid dephlogisticated muriatic acid. 



M. Berthollet §, a few years after the discovery of Scheele, 

 made a number of important and curious experiments on 

 this body ; from which he concluded, that it was composed 

 of muriatic acid gas and oxygen; and this idea for nearly 

 20 years has been almost universally adopted. 



Dr. Henry, in an elaborate series of experiments, made 

 with the view of decomposing muriatic acid gas, ascertained 

 that hydrogen was produced from it by electricity; and he 

 attributed ihe phenomenon to water contained in the gas ||. 



In the Bakerian lecture for 1808, I have given an account 

 of the action of potassium upon muriatic acid gas, by which 

 more than one-third of its volume of hydrogen is produced; 

 and I have stated, that muriatic acid can in no instance be 

 procured from oxymuriatic acid, or from dry muriates, un- 

 less water or its elements be present. 



Tn the second volume, of the Memoires d'Arcueil, MM. 



* Communicated to the Royal Society at the request of the Managers of 

 the Royal Institution, 

 f From the Philosophical Transactions for 1809, Part JI. 

 $ Mem. Acad. Stockholm for 1774, p. 94. 

 $ Journal de Physique, 1785, p. 325. j| Phil. Trani. for 1800, p. 191. 



Gay 



