Clover as a Preparatory Crop for Wlieaf. 
423 
and to an abundance of roots, containing when dry from 1| to 2 
per cent, of nitri)gen. 
6. The clover-roots are stronger and more numerous, and more 
leaves fall on the ground when clover is grown for seed, than 
when it is mown for hay ; in consequence more nitrogen is 
left after clover-seed than after hay, which accounts for wheat 
yielding a better crop after clover-seed than after hay. 
7. The development of roots being checked when the produce, 
in a green condition, is fed off by sheep, in all probability leaves 
still less nitrogenous matter in the soil than when clover is 
allowed to get riper and is mown for hay ; thus, no doubt, 
accounting for the obse-rvation made by practical men that, 
notwithstanding the return of the produce in the sheep-excre- 
ments, wheat is generally stronger and yields better, after clover 
mown for hay, than when the clover is fed off green by sheep. 
8. The nitrogenous matters in the clover-remains on their 
gradual decay are finally transformed into nitrates, thus affording 
a continuous source of food, on which cereal crops specially 
delight to grow. 
9. There is strong presumptive evidence that the nitrogen 
which exists in the air in the shape of ammonia and nitric acid, 
and descends in these combinations with the rain which falls 
on the ground, satisfies, under ordinary circumstances, the require- 
ments of the clover-crop. This crop causes a large accumula- 
tion of nitrogenous matters, which are gradually changed in the 
soil into nitrates. The atmosphere thus furnishes nitrogenous 
food to the succeeding wheat indirectly, and, so to say, gratis. 
10. Clover not only provides abundance of nitrogenous food, 
but delivers this food in a readily available form (as nitrates) 
more gradually and continuously, and consequently with more 
certainty of a good result, than such food can be applied to the 
land in the shape of nitrogenous spring top-dressings. 
Laboratory, 11, Salisbury-square, Fleet-street, E.C. 
July, 1868. 
XXVII. — On the Cultivation of Waste Lands on Mountain-sides. 
By J, A. Slater. 
In discussing the question how moorlands can be rendered pro- 
ductive, it should be stated at the outset that if situated at very 
high elevations above the level of the sea, it is questionable 
whether their cultivation can ever be rendered remunerative. 
The barren moorland, whose cultivation I am about to describe, 
lies at an elevation of some 750 feet ; and is therefore not in the 
most favourable climate for agricultural purposes. The soil of 
