On the Valuation of Unexhausted Manures. 
19 
Such a manufactured guano would rank in a position inter- 
mediate between the more highly or purely nitrogenous manures 
(such as nitrate of soda and sulphate of ammonia) on the one 
hand, and a superphosphate of lime on the other ; or rather, it 
would be equivalent to a mixture of the two. 
Other manure-dealers also prepare " dissolved guano," but of 
very varying composition. 
From what has been said in regard to the action, and the 
value, of different descriptions of manuie, it will be readily 
understood that the value of guano will depend very greatly 
upon the percentage of nitrogen it contains. The nitrogen 
in guano, whether " dissolved " or not, should be valued at the 
rate for the time of that in nitrate of soda, or sulphate of 
ammonia. 
If the guano be " dissolved " by admixture with sulphuric 
acid, the value of the phosphates rendered soluble may be 
reckoned as the same as that in superphosphate of lime, but if 
not dissolved at only two-thirds as much. 
Thus it will be obvious that the mere price paid for guano 
cannot be accepted as the basis upon which to calculate the 
value of its unexhausted residue after it has yielded a crop. It 
is essential for the establishment of a claim for compensation 
that the composition of the guano should be known, and its 
actual value calculated, according to the amount of ammonia it 
contains or yields, the amount and condition of its phosphates, 
the price of ammonia in sulphate of ammonia, and that of 
soluble phosphate in superphosphate. 
If the guano have been acted upon by sulphuric acid, both its 
nitrogen and its phosphates will probably be more effective on the 
first crop, and leave, therefore, the less for succeeding crops, than 
if it were used in its natural state. But the difference would not 
be either sufficiently great, or sufficiently uniform on various 
soils and in various seasons, to justify a difference in the scale of 
valuation of the unexhausted residue. 
If guano, whether dissolved or not, have been used for roots 
consumed upon the farm, and the manure so produced has not 
yielded a crop, 155. for 20s. estimated value of the guano may 
be allowed if the roots be consumed on the land, or 14s. if in the 
yards. If the manure produced from the roots have yielded a 
(;orn-crop, the corn being sold and the straw left, 4;?. for 20s. 
value of the guano should be allowed ; if a second corn-crop 
have been taken, Is.; or if, instead of a second corn-crop, grass 
or hay be grown and consumed, 2s. 
If guano, whether dissolved or not, have been directly applied 
for a corn-crop, the grain sold, and the straw left, 6s. for 20s. 
value of the guano might be awarded. If after one corn-crop, 
c 2 
