00 MODERN HIGH FARMING. 



Presuming, therefore, that it originally weighed 10 ounces, it will 

 then only weigh 9)^ ounces, and nothing but water having been lost, 

 these 9*^ ounces will now contain 12 per cent, of phosphoric acid. 



If the manure be purchased upon this sample without further 

 analysis, as frequently occurs, the buyer will pay on the basis of 

 12 per cent, but will, in reality, only receive 10 per cent, and so incur 

 a loss of $1.50 or $2.00 per ton. 



In many instances, farmers are induced to buy manures at so 

 much per ton, guaranteed to contain, in the dry state, certain propor- 

 tion of the active elements. When analyzed, they are found to be 

 loaded with 20 or even 25 per cent, of water; and therefore, if sold as 

 containing, say, 20 per cent, of acid phosphate, will only contain 15. 



ORGANIC MATTER consists of all substances subject to decom- 

 position by fire, or to natural decay: hair, wool, woody fibre, 

 cotton, vegetable and animal refuse, are consequently placed in this 

 category by the chemical analyst. The value of their presence lies 

 in their percentage of nitrogen, and this being very variable indeed, 

 the addition of the words nitrogenous, or non-nitrogenous, and the 

 indication of the equivalent quantity of ammonia, should always be 

 demanded. Where this precautionary measure is neglected, very 

 grave misapprehensions frequently ensue, from the simple fact that 

 common wood-shavings, mixed into a manure, would be truly stated 

 as organic matter. 



When these words are qualified by that of " nitrogenous," a 

 glance at the foot of the certificate should show us the equivalent 

 in ammoniacal salts. Thus in Peruvian guano, it was no uncommon 

 thing to find 50 per cent, of nitrogenous organic matter, containing 

 17^ per cent, of ammonia, and equal to 14)^ per cent, of nitrogen ; 

 and hence the prevalent custom for unprincipled traders to manu- 

 facture spurious guanos, which were bought by the unsuspecting 

 farmer, under the impression that the term " organic matter" was 

 just as significant of value in the one case as in the other. 



SOLUBLE PHOSPHORIC ACID represents, as we have already pointed 

 out, the quantity of phosphate of lime made soluble in water by the 

 excess of sulphuric acid. For example: a superphosphate of 12 per 



