MODERN HIGH FARMING. 31 



We reply to this that, while quite prepared to accede in the very 

 fullest manner to all the claims of long practice, and while admitting 

 that some crops may be annually produced, it has frequently 

 occurred in our experience that the addition of some essential ele- 

 ment to the soil, discovered by chemical investigation to exist there in 

 insufficient quantity, has been the means of immediately doubling the 

 quantity previously produced of those very crops and greatly height- 

 ening their quality. 



Thus, for example, it is very desirable to know how much lime a 

 soil contains, since the different combinations which it facili- 

 tates or into which it enters, produce sweet, sound and nutritious 

 green crops, full eared grain, and fine strong straws. If a soil con- 

 tain too little or no lime, none of these advantages can accrue, and 

 yet the farmer may have expended considerable sums in the purchase 

 of other fertilizers, and will not comprehend their inefficiency until 

 his attention is directly called to the absence of lime. 



Again, it is necessary to know the proportion of combustible or 

 organic matter contained in a soil, since upon their abundant pres- 

 ence depends the fixation of a greater or lesser quantity of nitrogen. 



And yet again, there may be present some of those injurious com- 

 pounds of iron or salt already described, or an excess of clay or of 

 sand, or too much water, etc. 



The whole of these cases, a 1 though of great importance, are mere- 

 ly elementary; for we must remember that in addition to them 

 we require to know how much ammonia, nitric acid, phosphoric acid, 

 potash, and many other elements a soil contains before we can form 

 any just appreciation of its value. 



Before proceeding to investigate the chemical constituents of a 

 soil, it is, as we have seen, necessary to rigorously examine its 

 physical properties, they being the real basis upon which everything 

 subsequently depends. 



No man in his right senses would attempt to build a house on 

 moving sands, and just in the same way it would be futile to seek 

 to introduce chemical elements into a soil, if it were found to be 

 physically incompatible with vegetation and high-class culture. 



