186 EF. W. Milgard— Objects and Interpretation of Soil Analyses. 
pare others therewith; but even a cursory comparison shows 
that, in many cases, soils showing percentages of plant-food very 
much inferior to those of the type are nevertheless in practice 
found quite as productive; and that even in cases where pre- 
cisely the same solvents had been used in their extraction. 
These facts are too well known to require exemplification ; and 
they led to the exclusive adoption, in the study of the part 
played by the several soil ingredients, of the methods of culture 
on artificial soils or in solutions of known composition. 
The radical fault of these methods is that they necessarily 
deal with plants placed under artificial conditions, and with 
mediums of nutrition whose comparison with natural soils is at 
best a lame one; necessarily so, until we shall know much 
more than we do of the intimate condition and functions of the 
soil as a whole, and of its ingredients, both severally and 
jointly. And while the artificial cultures have given us some 
the large scale; and when a particular kind of manure finally 
fails of effect, to go and try again; and so on. 
Are we then really reduced to such empiricism as this—are 
the permutations and combinations of nitrogenous, phosphate 
and potash manures, all that agricultural chemistry can do for 
the western farmer, when his “inexhaustible” soil begins to be 
“tired ?” 
t is evident that when used in this connection, and made 
uniformly and systematically, with a definite problem in views 
