516 Report of Experiments with different 31anures 
year to year. In 1860 tliey amounted on the average to twice as 
mucli as in 1859 ; in 1861 to considerably less than in 1860, but 
generally to at least 1^ time as much as in 1859; and in 1862 
in most cases to nearly as much and in some to considerably 
more than 1860. 
Without manure, the after-grass of 1859 was estimated as equal 
to something less than 8 cwts., that of 1860 about 19 cwts., that 
of 1861 nearly 14 cwts., and that of 1862 about li)^ cwts. of hay. 
With farmyard manure the amounts were scarcely 10 cwts. in 
1859, more than 21^ cwts. in 1860, nearly 16 cwts. in 1861, and 
over 21 cwts. in 1862. With the heavy dressings of mixed 
mineral manure and ammonia-salts they ranged from about 11 to 
nearly 15 cwts. in 1859, from over 21 to over 22 cwts. in 1860, 
from about 16 to j^bout 18 cwts. in 1861, and from about 17 to 
about 24 cwts. in 1862. 
Comparing more directly the effects of the different manures 
on the amounts of after-grass, it is seen that the quantities varied, 
in 1859 from under 8 cwts. without manure to about 14f cwts. 
with the heaviest artificial manuring ; in 1860 from about 
19 cwts., to about 22 cwts. ; in 1861 from about 13J cwts. to 
over 18 cwts. ; and in 1862 from about 15^ cwts. to about 
24i cwts. 
The facts relating to the after-grass show, then, that the 
amounts varied very much both according to season and 
manuring, and that, when both were favourable, they were fre- 
quently equivalent to more than one ton of hay. Taking the 
average of the seven years, the after-grass without manure was 
estimated as equivalent to about 12J cwts. of hay per acre per 
amium, and that with the heaviest artificial manuring at nearly 
19 J cwts. 
CJiemical Composition of the Hay. 
In our former report on the composition of the hay grqwn by 
the different manures in the earlier years of the experiments 
(vol. XX., part 2), we treated of the proportions of — nitrogenous 
substance, fatty matter, woody fibre, other non-nitrogenous vege- 
table compounds, mineral matter (ash), total dry substance, and 
water; and to that more complete consideration of the subject 
we refer the reader. In treating, on the present occasion, of the 
composition of the hay grown in the fourth, fifth, sixth, and 
seventh seasons, attention will be confined to the proportions of 
dry matter, of mineral matter (ash), and of nitrogen ; and a few 
general observations on the circumstances affectizig tlie compo- 
sition may here be made, thereby rendering the indications of 
the results themselves the more readily understood. 
Comparing the hay of one season with that of another, a high 
