308 BULLETIN OF THE BUSSEY INSTITUTION. 
with the potassic and phosphatic manures than any single one. In 
many cases it might even be best to use no nitrate of soda whatsoever 
in the original mixture of fertilizers that is put upon the land before 
the seeds are sown;, though occasional small doses of the nitrate, 
applied judiciously from time to time while the crop is growing, could 
hardly fail to do good. It would of course be impossible to come to 
any conclusion of general applicability with regard to a question of 
detail so intricate as this. ‘The composition of the best possible mix- 
ture of fertilizers must necessarily vary with the peculiarities of position 
and the character of each particular farm. A chemist’s experiments 
can do no more than indicate the broad principles upon which the 
application of fertilizers depends. It belongs to the farmer’s art to 
apply those principles with such intelligence that the wished-for 
economic result shall be obtained at the least possible cost. 
It is to be observed that remarks of analogous character to those 
just made with regard to the nitrate of soda used upon square EE 2, 
would apply to almost any of the mixtures of fertilizers that were 
employed in my experiments. It is not at all probable that the nitro- 
genous constituents of any one of the mixtures were the best possible, 
either in respect to quality or to quantity, for the conditions of soil and 
moisture that obtained in the experiment. Itis probably true in general 
not only for the nitrogenous manures, but to a less extent for the phos- 
phatic and the potassic fertilizers also, as has been urged on page 127,that 
a certain advantage might be gained when using mixtures of commercial 
fertilizers, if these mixtures were prepared, not by taking a single 
kind of fertilizer out of each of the three great classes, as has been 
done in most of my experiments, but by choosing in an intelligent way 
several varieties of each of the three special classes. Not only is it 
likely that a mixture of nitrate of soda and sulphate of ammonia would 
generally do more good than could be accomplished by the same 
amount of nitrogen applied in the form of either one of these salts by 
itself, but a small gain of analogous character may probably be had 
by using judicious mixtures of sulphate, carbonate, and chloride of 
potassium rather than any single one of these salts; and the same 
remark will doubtless apply to the application of bone-meal, or “ flesh 
meal,” or composted bone-black to the land, in connection with the 
use of a true superphosphate. But since either one of these sub- 
stances, if brought in contact with the superphosphate, would tend to 
