518 Report of Experiments with different Manures 
equal stage of growth or maturity ; but as, within limits, and 
under favourable conditions of soil and season, a moderate 
supply of nitrogen favours the ripening tendency, the crop more 
liberally dressed with nitrogenous manure may, at the same period 
of time, be at a more advanced stage of growth, and it might not 
then, as it otherwise would, show a higher percentage of nitrogen 
in its dry substance. 
Percentage of Dry Matter in the Hay. 
Table III. (p. 532), gives, for each plot, the percentage of dry 
matter in the hay as carted from the land, in each of the last 
four years, also the average percentages over the four, and the 
whole seven years of the experiments. 
Comparing the produce of one year with that of another, the 
order of highest percentage of dry matter was — 1859, 1861, 
1860, and 1862 ; and it may be observed that this result is 
quite consistent with the characters of the respective seasons 
for some time before cutting, and during the making the hay. 
The percentages of mineral matter in the dry substance will, 
however, show, that there was a real difference in the ripeness 
of the produce, as well as in its mere condition of dryness or 
dampness according to the weather immediately before the 
cutting and during the making. Thus, the produce of 1859 and 
1861, with higher percentages of dry matter than in that of I860 
or 1862, contained lower average proportions of mineral matter 
in the dry substance, indicating a greater degree of maturity. 
The percentage of .dry matter in the produce varied very 
much less comparing that grown by different manures in 
the same season, than comparing season with season. In 
fact, when it is borne in mind how many circumstances 
affect the condition of such complex and indefinitely ripened 
produce as hay according to the manure employed, it is only 
what we should expect, to find that the difference in the^ con- 
dition of the produce of two comparable plots may vary, or 
even be reversed, according to the characters of the season ; for, 
not only will the proportions of Leguminous, Graminaceous, or 
other herbage (which are each somewhat differently affected in 
development according to season) be very different according to 
the manure employed, but the prevalence of one Graminaceous 
plant over another, the tendency to leafy or stemmy growth, and 
the relative condition of ripeness, will also greatly vary. Tlius, 
with a hot and ripening season, the addition of nitrogenous to 
mineral manure may so increase the fixation of carbonaceous 
substance as to give a produce containing a higher proportion of 
dry substance ; whilst in a wetter and colder season the effect 
would probably be to give a relatively leafy and succulent 
