166 now CROPS feed. 



oury to cool. Then introduced into tlie various gases 

 named below, it absorbed as many times its bulk of them, 

 as are designated by the subjoined figures: 



Ammonia 90 Hydrochloric acid 85 



Sulphurous acid G5 Hydrosulphuric acid 55 



Protoxide of nitrogen 40 Carbonic acid 85 



Oxygen 9}^ Carbonic oxide 9)^ 



Hydrogen 1% Nitrogen 7)^ 



According to De Saussure, the absorption was complete 

 in 24 hours, except in case of oxygen, where it continued for 

 a long time, though with decreasing energy. The oxygen 

 thus condensed in the charcoal combined with the carbon 

 of the latter, forming carbonic acid. 



Stenhouse more lately lias experimented, in the same di- 

 rection. From these researches we learn that the power 

 in question is exerted towards different gases with very 

 unequal effect, and that different kinds of charcoal exert 

 very different condensing power. 



Stenhouse found that one gi'amme of dry charcoal ab- 

 sorbed of several srases the number of cubic centimeters 

 given below. 



Name of Gas. 



Ammonia 



Hydrochloric acid 



Hydrosulphuric acid. 



Sulphurous acid 



Carbonic acid 



Oxygen 



The absorption or solution of gases in water, alcohol, 

 and other liquids, is analogous to this condensation, and 

 those gases which are most condensed by charcoal are in 

 general, though not invariably, those which dissolve most 

 copiously in liquids, (ammonia, hydrochloric acid). 



Condensation of (iases by the Soil. — Reichardt and 

 Blumtritt have recently made a minute study of the kind 

 and amount of gases that are condensed in the pores of 

 various solid substances, including soils and some of their 



rHOPERTV OF 



KftM. COLLEGE LIBRARY. 



