containing Nitrogen. 473 
ture above-mentioned, the subsequent produce however was 
one-sizth more than any other land of the field. The oats 
sown with the tares grew extraordinarily after the application, 
and it is believed, that if applied earlier in the season to the 
tares as to the pasture, and during dry weather followed by 
less drought, the leaves of the plant would not have withered, 
and the effect would in both cases have been more marked. 
On the 21st of May a similar quantity, viz. one cwt. to the 
acre, of sulphate of ammonia was applied to a field of clover 
in dry weather: in this instance the leaves did not wither, but 
no increased growth appeared to be the consequence; and a 
similar result was obtained by the application of nitrate of 
soda. . 
To a field of podding peas much infested with slug, the 
following dressing was applied early in the morning, and by 
ten o’clock an immense number of the dead insect covered the 
Jand :— 
Sulphate of Ammonia .. 7} cwt. at 17s. Od. 6l. 7s. 6 
Common Salt........2 cwt.at 1 6 OESO 
Oil Cake, finely powdered 7 cwt.at 6 6 Roh «6 
this was sown broadcast, at the rate of 14 cwt. to the acre 
(value 14s. 6d.), and besides saving the plant by the destruc- 
tion of the insect, seemed in a short time to have converted 
this crop, from the worst of two others in adjoining fields, into 
the best of the three, and little or none of the withering effect 
on the leaves ensued. 
It will be observed from the above experiments, that sul- 
phate of ammonia appears to have acted better upon grami- 
naceous than upon leguminous plants; for though the crops 
of tares and peas seem both to have received considerable 
benefit from the application, such benefit was by no means in 
proportion to the effect produced upon wheat or oats; the 
oats sown with the tares, as has been before observed, growing 
surprisingly after the application, and exhibiting a marked 
distinction in their rate of increase. 
Sulphate of ammonia, as well as nitrates of soda and potassa, 
comes under theclass of stimulating manures ; that is, such ma- 
nures which, at the same time that they supply the plant with 
one or more ingredients necessary to the crop, enable it to 
obtain a larger supply of its usual nourishment from the soil 
and the atmosphere: hence the quantity of nitrogen itself in the 
crop from the land to which a nitrogenous manure has been 
applied, is greater than the sum of the nitrogen from the un- 
manured portion and the quantity contained in the manure so 
added ; and hence the result of the application of a given quan- 
tity of such manure will vary upon different soils, and even 
