On the Valuation of Unexhausted Manures. 
605 
manure-value of a ton of linseed-cake consumed, which was 
previously reckoned at 4Z. 12^. 6rZ., is now taken at 3/. I85. 6f/. ; 
that of a ton of maize is reduced from IZ. \\s. to \l. os. Id. ; 
and that of other foods in varying proportions, depending partly 
on the alteration (if any) in the adopted average composition 
of the foods, but mainly on the reduction in the money-value 
assigned to ammonia. 
III. Unexhausted Manure-value of Cattle Foods. 
So much for the method, and the results, of the estimation 
of the total or orifjinal manure -value of the different foods, 
deducting merely the nitrogen, the phosphoric acid, and the 
potash, estimated to be retained by the animal consuming them. 
We have now to attempt the still more complicated and difficult 
task of endeavouring to estimate the unexhausted manure-value 
of the different foods, or what may be called their compensation- 
value, after they have been used for a series of years by the 
outgoing tenant, and he has realised a certain portion of the 
manure-value in his increased crops. 
As already said, we have in the case of a number of the foods 
endeavoured to estimate the probable amounts of increase that 
the tenant would obtain in his barley and wheat crops, sup- 
posing that the food were used at the rate of one ton per acre 
in eight years, or one ton over 8 acres each year ; and then, 
after making allowance for loss, we have estimated the value 
of the unexhausted residue at a declining rate from the last to 
the eighth year. These results gave a basis for consideration, 
and, having studied them, and settled what seemed to be a 
suitable allowance, we have fixed upon a scale of reduction, 
starting from the original manure-value as estimated in Table II. 
The rule so determined upon is to deduct one-half of the 
original manure-value of the food used the last year, and 
one-third from year to year each year to the eighth, in the case 
of all the more concentrated foods, and the roots, in fact of all 
the foods in the list excepting the hays and the straws; and 
for these, which contain larger amounts of indigestible matter, 
and the constituents of which will be more slowly available 
to crops, two-thirds of the original manure-value is deducted for 
the last year, and only one-fifth from year to year to the eighth 
year. 
The results of the estimates of compensatioii-value so made 
are given in Table III, (p. 606). The first column shows the 
total or original manure-value of each food. The second column 
shows the allowance for the last year, and the succeeding seven 
columns that for each succeeding year to the eighth. The last 
