in its different States. 353 



Gay Lussac and Thenard have detailed an extensive series 

 of facts upon muriatic acid and oxy muriatic acid. Some 

 of their experiments are similar to those I have detailed in 

 the paper just referred to; others are peculiarly their own, 

 and of a very curious kind : their general conclusion is, that 

 muriatic acid gas contains about one quarter of its weight 

 of water ; and that oxvmuriatic acid is not decomposable 

 by any substances but hydrogen, or such as can form triple 

 combinations with it. 



One of the most singular facts that I have observed on 

 this subject, and whjeh I have before referred to, is, that 

 charcoal, even when ignited to whiteness in oxymuriatic or 

 muriatic acid gases, by the Voltaic battery, effects no change 

 ID ihcm ; if it has been previously freed from hydrogen and 

 moisture by intense ignition in vacuo. 



This experiment, which I have several times repeated, 

 led me to doubt of the existence of oxygen in that sub- 

 stance, which has been supposed to contain it above all 

 others in a loose and active state; and to make a more ri- 

 gorous investigation than had been hitherto attempted for 

 its detection. 



If oxymuriatic acid gas be introduced into a vessel ex- 

 hausted of air, containing tin ; and the tin be gently heated, 

 and the gas in sufficient quantity, the tin and the gas dis- 

 appear, and a limpid fluid, precisely the same as Libavius's 

 liquor, is formed : — it occurred to me, that if this substance 

 is a combination of muriatic acid and oxide of tin, oxide of 

 tin ought to be separated from it by means of ammonia. I 

 admitted ammoniacal gas over mercury to a small quantity 

 of the liquor of Libavius; it was absorbed with great heat, 

 and no gas was generated; a solid result was obtained, 

 which was of a dull white colour; some of it was heated, 

 to ascertain if it contained oxide of tin ; but the whole vo- 

 latilized, producing dense punarent fumes. 



Another experiment of the same kind, made with great 

 care, and in which the ammonia was used in great excess, 

 proved that the liquor of Libavius cannot be decompounded 

 by ammonia; but that it forms a new combination with 

 this substance. 



I have described, on a former occasion, the nature of 

 the operation of phosphorus on oxymuriatic acid, and I 

 have stated that two compounds, one fluid and the other 

 solid, are formed in the process of combustion, of which 

 the lirst, on the generally received theory of the nature of 

 oxymuriatic acid, must be considered as a compound of 

 muriatic acid and phosphorous acid. It occurred to me, that 



Vol. 36. No. 151. AW. 1810. Z if 



