On the Valuation of Unexhausted Manures. 
595 
A great advance has thus been made ; and in discussing the 
question of the unexhausted residue of manures, upon which we 
now propose to enter, it is a great advantage to know that agri- 
culturists are ready to accept it as an established fact that the 
chemical composition of a food affords a true indication of ifs 
manure-value. Further evidence of improved knowledge is to 
be found in the fact that the relative market prices of different 
cattle-foods gradually approximate more nearly to what may be 
called their relative scientific values — that is, their values taking 
into account both their feeding- and their manure-value. For 
example, ten years ago the price of linseed-cake ranged from 
12Z. to 14/. per ton, whilst decorticated cotton-cake was hardly 
saleable at half the price ; linseed-cake being more valued as 
food, and the greater manure-value of cotton-cake not being 
recognised. Now, however, the relative market prices of the 
two foods much more nearly represent their true relative 
values, taking both their food and their manure values into 
account. 
The discussions which have taken place in connection with, 
and subsequent to, the passing of the " Agricultural Holdings 
Act of 1883," which gives to the tenant the right of property in 
his unexhausted manures, have afforded the means of ascertain- 
ing the general views of agriculturists on the subject ; and 
although some exaggerated opinions have been put forward, 
common-sense views have, upon the whole, prevailed ; and we 
are encouraged to believe that any carefully considered contri- 
bution to the solution of this most complicated and difficult 
question will be favourably received, and will not be without 
practical value. 
The existence of unexhausted fertilitij, resulting from the 
consumption of cattle-foods, depends upon the fact that when 
organic matter, animal or vegetable, is applied to the soil as 
manure, its complete decay, and the complete liberation of its 
fertilising constituents, extend over a considerable period of 
time. Poor land cannot be suddenly brought into '■'■condition'''' 
by the consumption on the farm of purchased foods. Nor can 
" condition" that is accumulated fertility, be at once withdrawn 
by suddenly stopping the use of the foods. 
The Rothamsted field experiments afford numerous illustra- 
tions of such gradual accumulation, and only gradual exhaustion. 
It may take a great many years of unmanured cropping to 
exhaust the accumulation from a few years' application of dung, 
and to bring the land back to its original state. Even when 
rape-cake is applied for the continuous growth of corn-crops, 
a considerable unexhausted residue remains in the soil. The 
fact that such accumulation does take place cannot be disputed. 
