178 [Assembly 



all the barrels; the brown liquor will pass through the barrel of 

 pure sand unaltered, its color will remain dark, and its odor 

 offensive; but that which runs through the barrels containing char- 

 coal or clay will have lost both color and smell, clearly showing 

 that to these ingredients the soil owes its property of retaining the 

 requirements of plants from solutions. It is true that some other 

 ingredients in the soil have similar powers, but to a very limited 

 extent, as compared with carbon and alumina. 



The next question which naturally arises is : will these con- 

 stituents detain gases as readily as materials in solution 1 The 

 answer is, yes; and the proofs equally simple. A wire sieve sus- 

 pended in the upper part of the well-hole of a privy, and of its 

 full size, and filled with charcoal, will receive and retain all the 

 gases as they rise, so as to render the privy inodorous. A coating 

 of charcoal on a compost heap, if sufficient in quantity, will re- 

 ceive and retain all the escaping gases, and alumina will do the 

 same if divided with some other material, so as to present a suf- 

 ficient amount of clay surface to receive the gases. Night soil, 

 when mixed with charcoal or clay, is rendered entirely inodor- 

 ous, and indeed, when mixed with decomposed muck, which 

 contains carbon, the same effect is produced. The refuse 

 liquor of gas houses, when thoroughly stirred in a magma or semi- 

 solution with clay, loses its odor, and is thus the best manure, and 

 in the best form to apply to poor, sterile, sandy soils. Carbon 

 (charcoal), when mixed with this fluid waste, in the same way, 

 produces a similar result; and even woods-earth, or headlands, 

 from the amount of carbon they contain, are good deodorizers. 



If a quantity of charcoal dust heated red hot, and then suf- 

 fered to cool in a close vessel, be afterwards divided into two par- 

 cels, the following experiment may be made, which will clearly 

 establish the fact that carbon is capable of absorbing gases ; 



Exclude one half the carbon from the atnrosphere; place the 

 other half in a sieve, and suspend it over a fermenting manure 

 heap for a few hours, then apply these two portions of the char- 

 coal to separate pieces of land, of the same quality, and contain- 

 ing the same crop. The result will be that the charcoal charged 



