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mal black are annually used for the fertiliza- 

 tion of the soil, much of which has even been 

 imported from abroad. The syrup contained 

 in this residue, by its fermentation, generates 

 alcohol and then acetic and lactic acids, which 

 are unfavourable to the development of plants, 

 and hence the use of this residue, imme- 

 diately after its removal from the filters, 

 will prove disadvantageous. If, however, it 

 is left in heaps for a month or two before 

 being applied, the prolonged action of the air 

 transforms the animal matter and generates 

 ammonia, which not only neutralizes the 

 acids resulting from the fermentation of the su- 

 gar, but even imparts an alkaline reaction to 

 the product ; a reaction always favourable to 

 vegetation. Payen found in a quantity of ani- 

 mal black representing two hundred and 

 twenty-five pounds blood, 2.04 per ct. of ni- 

 trogen, but the results given by this manure 

 are greater than could be expected from this 

 proportion. This black costs in Paris from 

 60 to 75 cts. per 100 pounds. 



