542 
Value of Artijicial Manures. 
culations ; thus by multiplying the percentage of an ingredient 
of the analysis by the value by one per cent, of it as given in the 
Table, we at once arrive at the result. Thus — 
£. s. d. 
Organic Matter .. 17*0 per cent., at IfjfZ 0 18 
Soluble Phosphate lC-5 ,, at Gs. e^rf 5 7 11 
Insoluble Phosphate 13-0 ,, at Is. 5(/ 0 IS .5 
Sulphate of Lime 41-0 ,, at 0 8 2 
Alkaline Salts .. 2-0 ,, at 2i'^rf 00 5 
Ammonia .. .. 1-0 atlls. 2rf 0 11 2 
Giving 7 7 9 
as the price per ton ; the few pence difference in the calcula- 
tions being due to the neglect of small fractions in the calcula- 
tions of value per lb. in the previous instance. 
But by far the easiest method of arriving at the desired 
result, is by the use of the third column. This plan (which in 
justice I should state I first saw employed by Mr. Nesbit, who, 
to my knowledge, has used it for several years) consists in treat- 
ing the percentage of an analysis as so many parts of 100 tons 
of the manure — 20 per cent, means of course 20 parts in 100 — 
whether grains, lbs., or tons are in question. Now if we take 
one by one the substances mentioned in an analysis, and multiply 
the percentage quantities there given by the price of a ton of 
the particular ingredient, as ascertained by the Table, we shall 
obtain the aggregate cost of 100 tons. Nothing is then easier than 
to divide this amount by 100 in order to obtain the price of one 
ton. In fact this is accomplished by merely striking off two 
figures from the sum. 
I should here mention that although I have thought it neces- 
sary to give the exact sum in pounds, shillings, and pence, 
resulting from my calculations, it is quite unnecessary to go so 
minutely to work. To save calculation, therefore, the reader 
will see that he may in many cases dispense with the shillings 
and pence which figure in the cost placed against a ton of this 
or that ingredient of manure, and that he may adopt the nearest 
whole number for his standard. Taking for our basis the 
analysis of superphosphate before given, I proceed to ascertain 
its value by the use of the third column of the Table. 
In 100 Tons. 
£. s. 
Organic Matter .. (17 per cent.) 17 tons at IZ 17 0 
Soluble Phosphate (16^ , , ) 16^ tons at 32Z. 1.3s. 4d., say 33/. 644 10 
Insoluble Phosphate (13 ) 13 tons at 7Z SU 0 
Sulphate of Lime (41 ) 41 tons at 1/ 41 0 
Alkaline Salts .. ( 2 ,, ^2 tons at 1/ 2 0 
Ammonia .. .. (1 ) 1 ton at 56/ 5o 0 
751 10 
