270 CHEMICAL MANUEES. 



of this manure are recovered (in round numbers 3 cwts. manure per 

 ton of molasses) : — 



TABLE LXXYIL— SHO^YIXG VALUE AND A^.IOUXT OF MAXX'EE 



FEOM 1 TON MOLASSES. 



1000 kg. (1 metric ton) of molasses yield 



Fr. 

 150 kg. (3 cwts.) of organic manure with 6 to 7 per cent nitro- 

 gen and 6 to 7 per cent of potash ...... 16-60 



75 to 80 kg. (165 to 176 lb., say 1| cwt.) of sulphate of potash . 14-0 



Total 30-60 



whilst by the old pro3es3 only 90 kg. potash salts, worth 13 to 14 

 francs, were obtained. 



Labour is not more heavy than at the potash furnaces and the 

 work is less exhaustive, but there is the extra expense in coal and in 

 acid, which is valued at 5 francs (4s.) per metric ton of molasses. So 

 that the net profit to be drawn from the application of this process 

 over and above the potash salts usually obtained is about 12 francs, 

 say in round figures lOs. 



If these figures be applied to a factory working 20,000 tons of 

 molasses, the value of the bye-products to be obtained is 610,000 

 francs (£21,100), yielding a profit greater by 210,000 francs (£9600) 

 than that obtained from the potash salts alone. These figures show 

 very well the importance attached to the recovery of the nitrogen. 

 Vasssux's process is, moreover, wrought in Prance and Spain and 

 gives every satisfaction. 



Treatment of the Spent Wash by Biological Agents. — Jean 

 Effront has studied a new method of treating spent wash by 

 biological agents. The problem which he set himself was as 

 follows : To find an active substance (diastase) capable, in the con- 

 ditions of actual practice, of converting the organic nitrogen of 

 spent wash into ammouiacal nitrogen, the form under which it is 

 mosb easily recovered. This substance, called amidase, exists in 

 brewers' yeast. In the alcoholic fermentation the amidase of yeast 

 and foreign ferments always accompanying industrial fermentation, 

 does not intervene, owing to unfavourable conditions. It only 

 reveals its presence when the yeast finds "itself in an alkaline 

 medium and in a non-vegetative condition. After numerous but 

 very simple experiments which demonstrated to him the presence 

 of amidase in yeast and its power of converting amides into 

 ammonia, Etfront applied his discovery to the treatment of 

 distillery spent wash. This produces very large quantities of 

 ferment which is deposited at the bottom of the vats ; these fer- 

 ments separated from the fermented liquid before its distillation may 

 be used to treat spent wash. The method of working is as follows : 

 The spent wash issuing from the distilling colamn is cooled to 



o 



