On the Valuation of Unexhausted Manures. 
17 
When nitrate of soda is applied for a corn-crop, the grain sold 
bv the outg-oin<r tenant, and the straw left on the farm, he 
should receive G.s-. for 20.s-. cost of the manure ; nothing after a 
second corn-crop ; but if, instead of a second corn-crop, grass or 
hav be grown and consumed. Is. 
If nitrate of soda have been applied to grass which has been 
only pastured, 16s. for 20s. of original value of the manure 
should be allowed after one year, 10s. after two years, and 2s. 
after three years ; if hay have been taken and consumed, 14s. 
after the first year, 8s. after the second year, and Is. after the 
third year ; but if the hay have been sold, 2s. after one year, but 
nothing afterwards should be allowed. 
6. Sulphate of Ammonia. 
The only salt of ammonia used to any extent for agricultural 
purposes is the sulphate of ammonia. As already said, this is 
used to a considerable extent, but chiefly in the manufacture of 
mixed manures. When sown in the autumn it will be more 
1 iable to loss by drainage than when sown in the spring ; but 
when sown in the spring, it will probably be less liable to loss by 
(h ainage than nitrate of soda sown at the same time. It is more 
liable to such loss in the case of light and porous soils and 
subsoils, than of soils and subsoils of more retentive character. 
The same rules for compensation wdll be applicable to sulphate 
of ammonia as to nitrate of soda, provided the circumstances of 
its application, as above referred to, be the same. 
7. Superphosphate of Lime made from Mineral 
Phosphates. 
It has been explained that the phosphoric acid and the potass 
ot manures are comparatively little liable to loss by drainage, at 
any rate w^hen applied to the heavier soils. In fact, superphos- 
phate leaves a considerable unexhausted residue ; but that residue 
is, as a rule, without appreciable effect on succeeding crops, 
unless nitrogenous manure be applied to take it out. If, there- 
lore, the crop for which the manure has been applied has been 
wliolly sold by the outgoing tenant, no residue will remain to 
which a money-value can be assigned. 
The most prominent effect of superphosphate of lime when 
ajiplied to a root-crop is to cause a great development of root- 
fibres, thus enabling the plant to gather up much more of other 
food from the soil. It therefore serves to increase the imme- 
diate effect of other manures supplied with it ; also to turn to 
VOL. XI. — S. S. C 
