166 HOW CROPS FEED. 
eury to cool. Then introduced into the various gases 
named below, it absorbed as many times its bulk of them, 
as are designated by the subjoined figures: 
e 
PAUMMMOMED 5 op oie 0 wort ble 90 Hydrochloric acid....... 85 
Sulphurous acid......... 65 Hydrosulphurie acid..... 55 
Protoxide of nitrogen....40 Carbonic acid........ a ee 
CPR OOM Jo csatataeess out 9144. -Curbonic oxide Joye ceee 916 
Pplvatets 125 Ft es ave os 13% Nitrogen... ses 05 ese Ug 
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 has 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 gramme of dry charcoal ab- 
sorbed of several gases the number of cubic centimeters 
given below. 
Kind of Charcoal. 
Name of Gas —— SSeS 
Wood. Peat. | Anétmal. 
Ly) es |e | apres 
VANONIIMNTIT ED Soo disor dota «18 nates & = 9.928 m jaro eee wdislapere ee 98.5 96.0 | 435 
FIVUPOGRIGNIC ACLGS. 22 i2\5 32. tinh. ist pape aoe 45.0 60.0 | 
FIVArOsSnIPBUNIC: BCIGGS 22) sen see dainw nase. eee eee | 30.0 28.5 90 
SHIPRUVORS, ACOs 6.45.3 arp yes po atedenss eee ee | 32.5 27.5 17.5 
CAPPODIC ACI... recess sen Uses toa sees emits ; 14.0 10.0 5.0 
OPEN OND OF 2.) a 7ale asta ee > Dem = tk, se See ae 0.8 0.6 0.5 
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, hydrochlorie acid). 
Condensation of Gases 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 
