586 



On Dried Blood as Manure. 



too, that the butcher -will find the price paid to him for the blood too 

 small to compensate for the trouble and annoyance of keeping it on his 

 premises : and at this time large quantities are daily passed down the 

 sewers of London by those who formerly disposed of it to the col- 

 lectors. 



It is difficult to fix the exact value of dried blood. Supposing it to con- 

 tain as much nitrogen as the sample No. 3 above described, it would ulti- 

 mately furnish about 17 per cent, of ammonia. The price of ammonia must 

 not for agricultural use be higher than Qd. per lb., which would give the 

 nitrogen value of fully dried blood of the best quality as about 9Z. \Qs. per 

 ton ; but it is to be remembered that Peruvian guano furnishes not only 

 17 per cent, of ammonia, but 25 per cent, of phosphate of lime, with other 

 salts, for 9/. 10s. or 10/. per ton, so that ammonia in guano is considerably 

 cheaper than Qd. per lb. As a promsional price, I think that perhaps from 

 8/. to 9/. may safely be given by the agriculturist for genuine high-dried 

 blood — I say as a provisional price, because we want experience yet of 

 the precise action exercised respectively by ammoniacal salts and animal 

 matter only in process of decomposition. It may be that the high per 

 centage of carbonaceous matter supplied to the plant at the same time 

 with nitrogen or ammonia by blood, will considerably enhance its fertilizing 

 influence. The farmer's experience will decide ultimately what is the 

 true commercial value of this as of every other manure. 



The crop which dried blood will most benefit is wheat. To hops it 

 would prove an excellent manure : indeed, it would not fail to do good to 

 any kind of vegetation if properly employed. A mixture of dried blood 

 and mineral superphosphate of lime would be an admirable drill manure 

 for turnips. Dried blood is likely to be effective on all soils, but especially 

 on light sandy land. In conclusion, I would make a suggestion to manu- 

 facturers, based on theoretical considerations. The albumen of blood and 

 the white of egg are of the same composition, and resemble each other in 

 properties. The white of egg, when heated to a temperature of 165° or 

 170° Fahrenheit, coagulates, and becomes insoluble in water ; if, however, 

 it is allowed to dry at a temperature below that named, it becomes a 

 transparent brittle substance, which keeps for any time in its dry state, and 

 is soluble in water. The albumen which is contained in the watery parts 

 of blood equally coagulates with heat, and can equally be dried up without 

 coagulation by a moderate temperature. From its solubility in water, it 

 appears to me that it would be more active as a manure when so dried, 

 than when the coagulation which renders it insoluble is allowed to take 

 place ; and I would suggest that some means should be tried with that 

 end in view. I do not refer here to the separation of the clot of blood 

 upon standing, but to the further solidification on heating to the boiling 

 point. 



