90 On the Absorption of Gases 



results of our experiments to a near agreement, as the quan- 

 tities he has given in his appendix to that paper nearly ac- 

 cord with those I have stated in the second article. In my 

 experiments with the less absorbable gases, or those of the 

 2d, Su, and -Ith clas^aes, 1 used a phial holding 2700 grains 

 ofvvater, having a very accurately ground stopper ; in those 

 with the more absorbable of the first class 1 used an eudio- 

 meter tube properly graduated, and of aperture so' as to he 

 covered with the end of a finger. This was filled with the 

 gas, and a small portion expelled by introducing a solid 

 body under water : the quantity being noticed by the 

 quantity of water that entered on withdrawing the solid 

 body, ti>e fino;er was applied to the end, and the water 

 within aoitated: then^ removing the nnger for a mo- 

 ment under water, an additional tjuantity of water entered^ 

 and the aiiitation was repeated till no more water would 

 enter, when the quantity and quality of the residuary ga» 

 were examined. In fact, water could never be made to take 

 its bulk of any gas by this procedure ; but if it took 9-lOths,. 

 or any other part, and the residuary gas was 9-lOths pure, 

 then it was inferred that water would take its bulk of that 

 gas. The principle was the same in using the phial j only 

 a small quantity of the gas was admitted, and the agitation 

 was longer. 



There are two very important fiacta contained in the se- 

 cond article. The first is, thai the quantity of gas absorbed 

 is as the density or pressure. This was discovered by Mr. 

 WiiHam Henry, before either he or I had formed any theory 

 on the subject. 



The other is, that the density of the gas in th& water has 

 a special relation to that out of the water, the distance of 

 the particles- within being always some multiple of that 

 without. ThuSj ia- the case of carbonic acid, &c. the di- 

 stance within and without is the same, of the gas withiiv 

 the water is of the same density as without; in defiant gas 

 the distance of the particles in the water is twice that with- 

 out j in oxygenous gas, &c. the distance is just three times 

 aa great within as without; and in azotic, &c. it is four 

 times. This fact was th» result of my own inquiry. The 



former 



