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XV. On the Law of Absorption of Gases. By R. Bunsen*. 

 [With a Plate.] 



GASEOUS bodies are absorbed by liquids on which they 

 exert no chemical action, in quantities depending upon — 



1st. The essential nature of the gas and of the absorbing 

 liquid ; 



2nd. The temperature ; 



3rd. The pressure to which the gas is subjected. 



The volume of gas, reduced to 0° and m- 76 pressure of 

 mercury, which is absorbed by the unit volume of a liquid, 

 under the pressure of m, 76 is called the absorption-coeffi- 

 cient, or coefficient of absorption. The value of this absorption- 

 coefficient decreases in general with increase of temperature, in a 

 ratio dependent upon the chemical nature of the absorbed gas 

 and absorbing liquid. The values of the absorption-coefficients 

 for varying temperatures can only be determiued empirically. 

 An exact relation exists between the volumes of absorbed gasf 

 and the pressures under which the absorption takes place, the 

 amounts of gas absorbed varying directly as the pressure. 



The coefficient of absorption of any gas is therefore known 

 when the following quantities are given : — 1, the volume V, 

 before the absorption, reduced to 0° and P pressure ; 2nd, the 

 volume Vj remaining after the absorption reduced to 0° and P 1 

 pressure; and 3rd, the volume of the absorbing liquid. The 

 amount of gas absorbed by the volume h l of liquid under the 

 pressure P,, is equal to the difference between the volume of gas 

 originally taken, and that remaining unabsorbed, 



_ vp v,p, 



076 0*76 ' 



If the pressure daring the absorption had not been Pj but 076, 

 the amount of gas absorbed would have been, according to the 

 above law, 



X£_v 

 p, Y >- 



Hence it follows that the coefficient of absorption, i. e. the 

 amount of gas absorbed in the unit volume of liquid under the 

 pressure 0*76, is 



«4,("-.) « 



When the coefficient « is known, the amount of gas g absorbed 



* Communicated by the Author. The Editors are indebted to Mr. Roscoe 

 of Heidelberg for the translation of this memoir. 



t The expressions " amount of gas " or " reduced volume," are hence- 

 forward to be understood to signify the volume of gas reduced to 0° and 

 0" - 7ti pressure of mercury. 



