BULLETIN OF THE BUSSEY INSTITUTION. 127 
those given beyond, obtained by the use of single fertilizers. Thus 
Square BB 6, which received in 1873 nothing but 1336 grammes of 
pearlash, as it had in 1871 and again in 1872, gave a crop of 4.561 
kilogrammes of beans ; Square B 7, dressed with 307 grammes of sul- 
phate of potash, gave 4.612 kilogrammes of beans; BB 7, dréssed 
with 2267 grammes sulphate of potash, gave 4.322 kilogrammes of 
beans; and B 4, dressed with 4095 grammes of wood-ashes, gave 
4.734 kilogrammes of beans. Not a square in the entire list of those 
treated with mixtures yielded so large a crop of beans as was obtained 
from BB 4, which had received nothing but a very heavy dressing of 
wood-ashes for three successive years; it yielded, namely, in 1873, 
6.610 kilogrammes of beans, i. e. 39 bushels to the acre. Wood-ashes 
gave excellent results when used as a component of the mixtures (see 
G, GG, and H), as well as in the instances just cited ; and there can 
be little question but that, as a general rule, they would act better as 
manure than any single potash salt representing as much potash. 
Wood-ashes are more serviceable than any single potash salt, not only 
because they contain some phosphoric acid, lime, magnesia, and the 
other less valuable elements of plant-food, but because, considering 
them merely as a potassic manure, they contain a mixture of potash 
salts. It may be regarded as wellnigh certain that a given amount of 
potash, applied to the land in the form of appropriate mixtures of sul- 
phate, carbonate, silicate, and chloride of potassium, will, generally 
speaking, do more good than if all the potash were applied in the 
form of either one of these compounds. But in wood-ashes we find a 
mixture of these salts ready at hand; not the best mixture perhaps, 
but one already formed, and in this country, at least, very generally 
obtainable. 
I have little or no doubt but that the proportion of the phos- 
phatic and nitrogenous constituents in the mixed fertilizers employed, 
and often that of the potash also, might have been lessened very 
materially in almost every instance without appreciably diminish- 
ing the amounts of the bean crops. In other words, it would prob- 
ably have been better on some accounts if less “complete” mixtures 
had been employed upon a certain number of the squares of Section 
EE. The reasons for making the mixtures so complete were, first, 
the supposed inherent improbability that the supply of nitrogen and 
phosphoric acid in the land could be sufficient for a maximum crop ; 
