REFUSE OF THE SUGAR-HOUSE, ETC. 277 



of similar value. The animal charcoal of the sugar refinery, after 

 it has served its office there, is an admirable manure. It is, in fact 

 bone or ivory-black, mixed with the coagulated blood which has been 

 employed to clarify the sirup by entangling impurities, and a very 

 small quantity of sugar. This mixture, so rich in azotized princi- 

 ples, used actually to be turned into the sewers until the year 1824, 

 when M. Payen showed its value as manure, since which time near- 

 ly 10,000 tons have been annually employed in ameliorating the soil, 

 to the great advantage of practical agriculture. The importance 

 of the trade in this residue of the sugar-house, and complaints of the 

 occasional indiflferent quality of the article, attracted the attention of 

 the department of the Inferior-Loire in 1838, and led to the appoint- 

 ment of an inspector of the manure shipped from the port of Nantz. 

 I may here observe, that in testing a manure it is by no means 

 enough to limit attention to the quantity of organic matter which it 

 contains. The only sure means is to determitie the amount of azote • 

 it is not organic matter, but the amount of azotized organic matter 

 upon which almost alone depends the value of the manure. 



The residue of the sugar refinery is another of those articles 

 which presents an occasional anomaly in its application, and which 

 must not be left unnoticed. Its eflfect upon the ground has not only 

 been extremely variable, but it has sometimes happened that this 

 manure, laid on very soon after coming from the manufactory, has 

 been found decidedly injurious to vegetation. Kept for some time, 

 for a month or two» in a heap before being applied, its effect has no 

 only been found more certain, but also uniformly favorable. 



It is not difficult to explain these divers and opposite influences : 

 the sugar contained in the refuse undergoing fermentation yields 

 irst alcohol, and than acetic and lactic acids. Employed in this 

 state, the substance must necessarily prove injurious to vegetation. 

 It is only after it has lain for a sufficient length of time exposed to 

 the air, to have had the animal matter it contains changed into am- 

 monia, and the organic acids engendered saturated with this base, 

 that it becomes truly useful to vegetation. The heap indeed then 

 shows alkaline, not acid re-action.* 



The residue of the starch manufacturer, the fetid water which is 

 obtained in such quantity in the process of making starch from grain, 

 is a powerful manure, and ought not to be suffered to run to waste. 



The pulp or residue of the potato which is now produced in con- 

 siderable quantity in the potato starch manufactories, is known to 

 be an excellent article of food for hogs and cattle. Towards the 

 end of the season, however, it is apt to be of very indifferent quality, 

 and green food having by this time come in abundantly, it often 

 goes to the dung-hill. In the dry state, it is worth its own weight 

 of farm dung; wet, 100 of the pulp may be equal to about 131 of 

 farm-yard dung. The water which has served for washing out the 

 starch from the pulp, as in the case of wheat and other grain, coa- 

 tains an organic substance which when dried constitutes pulverulent 



* Payen and Boussingault, Ann. de Chimie, v. iii. p. 95, 36 seJie 

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