416 Rej)ort of Experiments teith differeiit Manures 
It will be found that the percentage of nitrof/en in the Dry 
substance, of such heterogeneous and irregularly ripened produce 
as hay, is, like that of the mineral matter, contingent upon many 
coincident circumstances. Still, the results will show, as already 
alluded to, that, other things being equal, the lower the condition 
of maturation of the produce the higher will be the percentage 
of Nitrogen, and vice versa. 
In accordance with this general observation, the Table shows 
that the season which gave the produce yielding the lowest 
average percentage of Dry substance, and the highest average 
percentage of Mineral matter in that dry substance (1856), gave 
also a produce containing a higher percentage of nitrogen in its 
dry substance than that of either of the years of higher condition 
of the hay. Conversely, the second season (1857), the produce 
of which showed the highest average percentage of dry matter, 
and the lowest average percentage of mineral matter in that dry 
substance, gave, at the time of cutting, a hay which contained the 
lowest average percentage of Nitrogen in that dry substance. As 
between the produce of one season with that of another, then, 
the general result was, that the more matured the condition of 
the hay, the lower was the percentage of Nitrogen in its dry 
substance. This is in general accordance with what we have 
elsewhere shown to obtain in the case of ripened crops — wheat 
and barley. It is true, that in the case of the hay-crop, the object 
is not a fully ripened produce. There is, therefore, of course, a 
limit below which a depreciation in the percentage of Nitrogen, 
the result of over-ripening, will be a disadvantage. At the same 
time we believe that, comparing the produce of hay of one season 
with that of another, each cut at its pioper stage of progress, 
that which has the lower percentage of Nitrogen in its dry sub- 
stance will, taking the average of seasons, have its constituents 
in the better condition of elaboration, and be, therefore, a better 
food for animals. 
The variations in the percentage of Nitrogen in the hay within 
one and the same season, according to the manuring, are very 
marked and interesting. 
Taking the average result of the three seasons, the produce 
grown on the plot manured with ammoniacal salts alone, con- 
tained a much liigher percentage of Nitrogen in its dry substance 
than did that grown without manure. Again, the produce grown 
by ammoniacal salts and sawdust gave a higher percentage of 
Nitrogen than that grown by sawdust alone. When the ammo- 
niacal salts were thus supplemented to the unmanured, or to th<; 
merely sawdusted conditions, the supply of Nitrogen was in con- 
siderable relative excess ; as was shown by the greatly increased 
produce wlion the mixed mineral manure was superadded. 
