NITROGEN FROM SPENT WASH. 271 



40" to 45° C. (104" to 113° F.), rendered alkaline by lime, soda, or 

 salts. One or two kilogrammes of yeast are added per hectolitre 

 and allowed to work for 3 or 4 days at 40° to 45° C. The conv< r- 

 sion of amides being finished, the ammonia is separated by distilla- 

 tion or by ventilation (Kestner method). By this latter method 

 the consumption of coal is about 50 kg. (say 1 cw^t.) per 100 

 hectolitres (2200 gal.) treated. By treating molasses spent wash, 

 100 hectolitres (2200 gal.) yield 40 to 45 kg. (88 to 99 lb.) of 

 nitrogen, representing a minimum value of 40 to 45 francs (32s. to 

 36s.). In spent wash from beets 100 hectolitres (2200 gal.) \ield 

 10 to 15 kg. (22 to 33 lb.) of nitrogen, worth 10 to 15 francs 

 (8s. to 12s.). The expense in fuel being 1 franc (9'6d.), the actual 

 profit is remarkable. 



Treating Spent Wash by Fermentation. — Beeryeast isnot the only 

 biological agent capable of converting the nitrogen of spent wash into 

 ammonia. Certain soil ferments likewise possess ths property. By 

 innoculating a solution of glutamine by garden soil, the formation 

 of ammonia can be demonstrated. Effront, using plate cultures, 

 has isolated three ferments acting on the nitrogen of spent w^ash. 

 One of them was recognized as the butyric acid ferment, and 

 Effront has closely examined the conditions which favour its am- 

 moniacal functions. In practice the general course of w^ork with 

 this ferment is analogous to that of the manufacture of alcohol. 

 There is a yeast chamber and fermentation vats; from the feiment 

 there is prepared a leaven equal to 5 to 10 per cent of the total 

 volume of the liquid to be fermented, and it is renew^ed every twenty- 

 four hours as in distillery brewing. To strengthen the ammoniacal 

 action, recourse is made to aeration to render the liquid strongly 

 alkaline, and to the use of agglutinants, such as sulphate of alumina, 

 which paralyses the development of ferments and produces a change 

 in the function of the cells. For the use of pure cultures, often far 

 from convenient, garden soil which mav be verv well taken as the 

 point of departure of ammoniacal fermentation, may be substituted. 

 Etfront recommends to sterilize this earth mixed w^ith the alka- 

 linized spent w^ash for an hour at 70° to 80° C. (158° to 176° F.), this 

 sterilization being sufficient to avoid the formation of noxious fer- 

 ments without destroying those with an ammoniacal function. 

 This soil culture in the spent wash may be used as leaven in the 

 same way as those made from pure cultures on condition that they 

 be renewed somewhat frequently. This process was experimented 

 on at the distillery of Quesnoy-sur-Deule, at the end of the season 

 1907-8. From the point of view^ of yield, the work leaves nothing 

 to be desired, and the amount of nitrogen extracted from the spent 

 wash from the manufacture of one hectolitre (22 gallons) of alcohol, 

 may be valued as 12 kg. (26-4 lb.) of sulphate of ammonia (say 1-2 

 lb. of sulphate of ammonia per gallon of alcohol). In the course of 



