The Agricultural Lessons of " The Eighties." 287 
points distinctly in this direction. " Thus," he says, " Hellriegel 
and Wilfarth have found, in experiments with various leguminous 
plants, that if a soil free of nitrogen have added to it a small 
quantity of soil-extract containing the organisms, that plants will 
fix much more nitrogen than was otherwise available to them in 
the combined form. It further seemed probable that the growth 
and crop-residue of certain plants favoured the development 
and action ot special organisms. It is admittedly not yet 
understood, either in what way the lower organisms affect the 
combination, or in what way the higher plants avail themselves 
of the nitrogen thus brought into combination." Again, " should 
it be finally established that such an action does take place in 
the case of certain plants, though not in that of others, it is 
obvious that part, at any rate, of the gain of nitrogen by the 
soil supporting the mixed herbage of grass-land may be due to 
the free nitrogen of the air brought into combination under the 
influence of the action supposed." This is careful writing, but 
seems to foreshadow important changes in our views regarding 
the assimilation of nitrogen by plants ; and if it can be shown that 
leguminous plants have this power directly, or through the 
agency of organisms in the soil, we may yet see our way to re- 
plenish our fields with nitrogen at less expense than at present. 
So far as other manurial questions are concerned, we are not 
able to report any particular advance upon previous knowledge. 
Something almost amounting to a tirade against farmyard 
manure, as an extravagant and expensive dressing, has been 
indulged in by certain writers. I have not space to discuss 
this matter, but would point out that the tendencies of the 
times are evidently against this view. The greater importance 
of live-stock in our economy involves the production of farm- 
yard manure ; and when stock- farming is best carried out, there 
is reason to regard the dung as a mere bye-product inevitable 
to the maintenance of stock, and consequently as a cheap mode 
of restoring fertility. The absolute necessity of dung for root- 
cultivation or for the production of winter food for stock, at once 
elevates it in importance, while at the same time the low price of 
corn cheapens its production. 
In the scientific use of foods much has lately been written 
upon the albuminoid ratio, and the fixing of dietaries upon this 
basis. Unfortunately for these theories, it must be allowed that 
Nature and agricultural practice have been beforehand, by pro- 
viding or recommending dietaries which do, in point of fact, 
contain the best proportion of carbo-hydrates to albuminoids. 
Also, the great variation in the composition of grass, hay, 
silage, turnips, straw, and cake, renders it impossible to draw up 
