NITROGENOUS MANURES 123 



matured garden crops will cause a prolonged growth 

 and very late maturity. 



Storer gives the following directions for preserving 

 any dried blood produced upon farms. 22 " The blood 

 is thoroughly mixed in a shallow box with 4 or 5 

 times its weight of slaked lime. The mixture is cov- 

 ered with a thin layer of lime and left to dry out. It 

 will keep if stored in a cool place, and may be applied 

 directly to the land or added to a compost heap." 



The price per pound of nitrogen in the form of 

 dried blood can be determined from the cost and the 

 analysis of the material. A sample containing 9 per 

 cent, of nitrogen and selling for $28 per ton is equiva- 

 lent to 15.55 cents P er pound for the nitrogen (2000 X 

 0.09 180. $28.00 -*r 180 = 15.55 cents). 



154. Tankage is composed.of refuse matter as bones, 

 trimmings of hides, hair, horns, hoofs and some blood. 

 The fat and gelatin are, as a rule, first removed by 

 subjecting the material to superheated steam. This 

 miscellaneous refuse, after drying, is ground and 

 sometimes mixed with a little slaked lime to prevent 

 rapid fermentation. 



Tankage contains less nitrogen but more phosphoric 

 acid than dried blood. Owing to its miscellaneous 

 nature, it is quite variable in composition, as the fol- 

 lowing analyses of tankage from the same abattoir at 

 different times show. 14 



First year. Second year. Third year. 



Moisture 10.5 9.8 10.9 



Nitrogen 5.7 7.6 6.4 



Phosphoric acid 12.2 10.6 11.7 



