266 WATER IN MURIATIC ACID GAS. 



ment with regard to the experiment, ought to have been ren- 

 dered favourable to the result, instead of being truly the re- 

 verse. 

 Fit conditions: The principal circumstances which I conceived required to 

 sel, heat ^e attended *°, were, to employ a much smaller vessel, to raise 



equally dif- it through its whole capacity to an equal heat, to have the part 

 liTed'TaiTat of the apparatus in which the water is to be condensed free 

 place of con- from salt, and to avoid, as far as practicable, the operation, 

 pressure* nor eillier of P ressure > or of a partial vacuum. It was nearly in 

 vacuum.' this manner, that the experiment was performed by Dr. Bostock 



and Dr. Traill, and hence their successful result, while Sir Hum- 

 phry, from not attending to these circumstances, was less suc- 

 Kepetition of cessful, though performing it on a much larger scale. Dr. 



exp. before Hope, anxious to ascertain the matter of fact, readily agreed 

 eminent men. , . , } ° 



to repeat the experiment with these variations ; Lord Webb 



Seymour and Mr. Ellis were present, and I haye his permission 



to communicate the result. 



Mur. of am. Ammoniacal gas, previously exposed for two days to dry 



irom dried potash, and muriatic acid gas which had been exposed to dry 

 gases was ex- . r .. ■ nj ,° .... , J 



posed to equal muriate or lime for 24 hours, were combined in a dry ex- 

 heat in a small hausted flask, of the capacity of 3*8 cubic inches. About QO 

 cubic inches of the acid gas were employed, and the flask re- 

 mained at the end filled with ammoniacal gas. The stop-co'ck 

 being removed without exposing the salt to the air, a glass 

 tube of four-tenths of an inch in diameter, previously fitted 

 by grinding to the neck of the flask, was inserted, its open 

 extremity dipping in quicksilver, and the flask being surrounded 

 with sand in an iron box, was placed horizontally on a chafing 

 dish, and fuel gradually introduced, so that the heat applied 

 was slowly raised. In a short time moisture appeared in the 

 tube, at a little distance from its insertion into the flask -, this 

 increased, proceeding to a greater extent along the tube, and 

 condensing in globules perfectly distinct, which, at different 

 periods of the experiment, covered the inner surface for a 

 length of three, four, or six inches -, and a small quantity col- 

 lected at the under part, which, with a very slight inclination 

 of the tube, moved slowly onward. At length the salt sub- 

 Water was ob- limed, and condensed in the tube close to the flask. The quan- 

 f u ine t d lu lz * tity of water, Dr. Hope was satisfied, appeared considerably 

 fourths of a larger than in Sir Humphry's experiment. The same quan- 

 fi rain > tities 



