Introduction 



proportions. He ought to know what kinds of 

 manure he should employ and to be able to calculate 

 the quantities that should be applied to various crops 

 and the seasons favourable for their application, so 

 that they will be most profitable to the plants for 

 which they are intended, and not be merely washed 

 away. 



He ought to know what manures can be com- 

 bined without fear of loss ; how to store them for 

 a length of time without appreciable loss ; how 

 to fix their value on the basis of the units of the 

 fertilising elements which they contain, and the 

 more or less favourable form in which these elements 

 are present. He must not blindly believe in the 

 virtue of manures, or listen to advertising recom- 

 mendations. He must demand a written guarantee 

 of the number of units of fertilising matter and the 

 forms in which they are presented, confirming these 

 facts by analyses, so as to pay a price, based on the 

 price of the day, corresponding to these units. He 

 ought to know the principal adulterations to which 

 these manures are liable, so as to be forewarned, 

 and exercise care so as to buy well and cheaply. 



Knowledge of the subject will prevent him from 

 paying too much for some manures much in demand, 

 which for this reason alone have attained a price 

 much beyond their real value. 



Finally, he ought to be able to account to him- 

 self for the produce which he has obtained per 

 unit of fertilising matter at the most advantageous 

 price at the farni, not forgetting the price of 

 transport, which, in the poorest manures, will be 

 proportionally higher to the unit. 



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