418 Report of Experiments with different Manures 
salts, the Table shows that, in both cases, the percentage of 
Nitrogen in the produce was considerably lower where the ammo- 
niacal salts were employed than in the comparable instances 
Avithout them. This lower percentage of Nitrogen in the hay, 
by the addition of ammoniacal salts to mineral manure, was 
partly due to the fact, that the produce grown by the mineral 
manure without the ammoniacal salts, contained so large an 
amount of the highly Nitrogenous Leguminous herbage, whilst 
that grown with ammoniacal salts in addition, was almost en- 
tirely Graminaceous. But the percentage of Nitrogen in this 
Graminaceous produce grown by ammoniacal salts together 
with a liberal supply of mineral constituents, was also very 
much lower than that in the equally Graminaceous produce 
where the nitrogenous supply was in excess ; that is to say, 
where the ammoniacal salts were used without the mineral 
manure. Thus, taking tlie average of the three years, the per- 
centage of Nitrogen in the dry substance of the hay grown by 
ammoniacal salts alone, was 1"9 ; whilst that in the dry substance 
of the produce grown by the same amount of ammoniacal salts, 
but in conjunction with the mineral manure, was only 1-4S. 
This produce grown by the nitrogenous and mineral manure 
combined, was about If time as great as that grown by the use 
of ammoniacal salts alone ; it was of a far lighter, and more 
lively green colour whilst growing ; it was far more luxuriant ; 
and it gave a much larger proportion- of flowering and seeding 
stem. Such were the comparative characters of the produce, 
which contained much the lower percentage of Nitrogen. The 
higher percentage of Nitrogen in the produce grown by the am- 
moniacal salts without the mineral manure was, therefore, coin- 
cident with a much smaller yield of hay, with a much less 
luxuriance of growth, and with a much larger proportion of leafy 
produce. In fact, in the case of hay, as in that of the ripened 
cereal grains, a relatively low percentage of Nitrogen (within 
certain limits) is, in cases comparable on the point, more likely 
to be associated with a relatively high, than with a relatively 
low condition, and degree of elaboration, of the constituents ; 
and it is also more likely to be tlie result of moderately luxuriant, 
than of either stunted or over-luxuriant growth. 
The points last referred to, are aptly illustrated by a comparison 
of the characters and nitrogenous percentage of the hay grown 
by the double amount of ammoniacal salts with the mineral 
manure, with those of the produce grown by the smaller amount 
of ammoniacal salts and tiie same mineral manure. The average 
percentage of Nitrogen in the dry substance of the scarcely too 
heavy or luxuriant produce grown by the mineral manure ami 
the smaller amount of ammoniacal salts, was only 1"48 ; whilst. 
