On Dried Blood as Manure. 



585 



I pve now the determination of nitrogen and water in three samples of 

 dried blood, made on the large scale at different times, and sent to me as 

 before mentioned : — 



Ammonia to 



Water. Nitrogen. which the Nitrogen 



is equal. 



Sample No. 1 . . 8*78 13-24 16-07 



No. 2 . . 7-91 13-58 16-49 



No. 3 . . 6-19 13-93 16-91 



It will be observed that this result is very satisfactory, the proportion of 

 nitrogen being in the last case nearly as high as in average samples of 

 Peruvian guano. The following analyses of other samples will show — 

 what hardly indeed requires demonstration — that in purchasing dried 

 blood it will be necessary that the farmer is assured that it is dry. Thus, 

 samples not externally moist were found to contain : — 



Moisture. Nitrogen. Equal to Ammonia. 



Sample No. 4. . , 21-81 11*44 13-89 



„ x\o. 5 . . . 29-46 10-45 12-69 



No. 6 . . . 22-11 11-38 13-82 



No. 7 . . . 35-43 8-74 10-59 



I would not be misunderstood to say that these samples have been 

 offered in the market as dry blood ; on the contrary, they have been sub- 

 mitted to me by the maker to determine lioic dry they were, in order that 

 a price might be fixed upon them. It is plain that a farther drying — easily 

 accomplished — will bring them up to the standard of other samples. 

 Altogether, therefore, I think we have a fair chance of getting, before 

 long, a good article of this kind on a practical scale. The quantity to be 

 obtained, and the jjrice at vrhich it may be purchased, are two other im- 

 portant questions. 



From an excellent article on blood, in Morton's Cyc-lopsedia of Agri- 

 culture,' to which the reader will refer with much advantage to himself, I 

 take the following sentence, with the explanatory note: — "The popu- 

 lation of Great Britain at the present moment is about 20 millions ; and if 

 we take 75 lbs.* as the average amount of flesh meat consumed by each 

 individual, we have 1,500,000,000 lbs. as the total animal food in one year. 

 And as the blood may be taken to represent at least one-fourteenth of the 

 net weight of an animal, the total weight of the blood of animals 

 slaughtered for food in England will be about 100,000,000 lbs., or 45,000 

 tons."' 



This statement refers, of course, to blood in its ordinary state ; and as it 

 loses three-fourths of its weight in drying, v, e should have about 11,000 

 tons of dried blood as the total quantity available under the very best 

 system of collection and preservation. 



How very far the quantity practically obtainable will fall short of this 

 estimate (supposing the calculations given in the extract we have made 

 to be correct), will at once be seen when it is considered that only the 

 blood of those animals that are slaughtered for thickly-populated towns 

 can be at all at the command of the manure dealer, and from this must be 

 further deducted the quantity used for feeding pigs, &c. It often happens. 



* ''In an Asylum containing, in ISII, on an average 116 persons (10 adults and 

 106 male and lemale children), the annual consumption of meat was 104| lbs.; and 

 in a private family in London, consisting of a gentleman, his wife, ten children, and 

 ten servants, in 1840, the consumption for each person was 370i- lbs. of meat.'" — Por- 

 ter s Progress of the Nation, p. 591. 



