

CHAPTER XV. 



CHEMICAL ANALYSIS HOW TO READ AND UNDERSTAND CHEMISTS' 



CERTIFICATES USE OF "COMPLETE" AND "SIMPLE" MAN- 

 URES CONCLUSION. 



If we were now asked to pithily sum up the great practical con- 

 clusion to be drawn from our lessons, we should reply, not ' ' Farmer, 

 know Thyself!" but, Farmer, know thy soils and analyze thy ma- 

 nure;" believing as we do, in all sincerity, that this is the sumof 

 intelligent high farming. 



The mere possession of an analysis, however, conveys no infor- 

 mation, unless it be thoroughly understood, any more than a hundred 

 pounds of candles would be of any service to a man in a dark room, 

 if he had nothing to strike a light with ; and we shall therefore en- 

 deavor to translate the meaning of the statements made by chemists 

 in their certificates. 



THE MOISTURE is the water which is introduced into the 

 mixture by the weak sulphuric acid, and in a properly prepared 

 compound should never exceed 12 to 15 per cent. The sellers of 

 chemical manures should invariably be required to guarantee a min- 

 imum of each active element contained in a given product, in its 

 normal state. 



Thus, for instance, a sample of superphosphate taken at the 

 works, may, when despatched by mail, have contained 20 per cent. 

 of moisture and 10 per cent, of soluble phosphoric acid; but between 

 the time of its dispatch, its arrival at destination, and its analysis 

 by the intending purchaser, so small a sample may have suffered the 

 loss of 5 per cent, in weight by evaporation. 



