240 EXPERIMENTS OF GASES ABSORBED BY WATER. 



from the general principle above ftated ; but, for all practical 

 purpofes, I apprehend, the law has been announced with 

 fufficient accuracy *. 

 Increafed tern- j n pj ace f t r, e coc fc Qt j cemented, in one experiment, a 



by condensation. ver y fenfible thermometer. The veflel was next filled with 

 mercury through the cock b ; and the tube B being alfo filled, 

 the cock b was (hut, and a bottle of carbonic acid gas fcrewed 

 on. The cock b being then opened, the mercury defcended, 

 and a meafured quantity of carbonic acid arofe into the veflel 

 A. In the fame way, a meafured quantit) of water was in- 

 troduced. When the denfity of the air was fuddenly doubled 

 by a column of quickfilver, the mercury in the thermometer, 

 whofe bulb was ftill furrounded by the condenfed gas, rofe 

 about l£ degree. On agitating the veflel, till the water en- 

 compafled the bulb of the thermometer, an elevation of barely 

 \ a degree enfued in the temperature of the water. This 

 afcent would probably have been greater, if the evolved heat 

 had not been carried off by the mercury on which the water 

 iloated. 



Munchejler, Dec. 8th, 1802. 



APPENDIX.— (Since read.) 



SINCE my paper was finifhed I have found that the num- 

 Coj*ecYions of bers afligned in it, as indicating the quantities taken up by 



the forTrin '" W ^ f ° f f ° me ° f the m ° re abforbable > a " d of aI1 of the Iefs 

 paper. abforbable gafes, are rather below the truth. The accuracy of 



thefe numbers I was led to doubt by a fufpicion that due at- 

 tention had not always been paid, in my former experiments, to 

 the quality of the unabforbed refiduum. For, the theory which 

 Mr. Dalton has fuggefted to me on this fubject, and which ap- 

 pears to be confirmed by my experiments, is that the abibrp- 

 Abforption of tion of gafes by water is purely a mechanical effect, and that 



gafes is purely j^ g arnoun t j s exactly proportional to the denfity of the gas, con- 

 mcchamcal. ■ • ' •: J * " r . . T' J ... . . * ' 



iidered abitractedly from any other gas with which it may ac- 

 cidentally be mixed. Conformably to this theory, if the re- 

 fiduary gas contain \, T \y, or any other proportion of foreign 

 gas, the quantity abforbed by water will be f, T %, &c. fliort 

 of the maximum. The proof of thefe propofitions would 

 lead me into a minutenefs of detail not fuited to the prefent 

 occafion, I therefore haften to communicate the refults of my 

 lateft experiments. 



The 



