APPLICATIONS OF LACTIC ACID FERMENTATION 119 



been discussed at some length in dealing with the preparation of 

 starters for the ripening of cream, and the process does not differ 

 materially from that described under the souring of cream. 

 Blichfeldt l has devised an appliance for the continuous souring of 

 separated milk, consisting of a closed cylindrical vessel into which 

 fresh separated milk is introduced, and from which soured skim 

 milk is withdrawn simultaneously. The contents of the vessel 

 are kept stirred, and J>y regulating the temperature and the rate 

 of output, the acidity of the product may be kept constant. The 

 apparatus is worked under sterile conditions as far as the avoidance 

 of infection from outside is concerned, while the fresh separated 

 milk must be efficiently pasteurised before use, which of course is 

 also the case in the tank souring process. The continuous process 

 has the advantage that by its means a large amount of milk may 

 be treated in a relatively small space. 



The Preservation of Stable Manure by addition of Whey. This 

 process has been proposed by Barthel 2 , and will have economic 

 value where whey is plentiful and peat is unobtainable. The lactic 

 acid fixes the ammonia in a form easily available for the nutrition 

 of plants (or the nitrifying bacteria). By using 50 to 100 litres of 

 whey per 1,000 kilos of manure, at a cost of about Id., the increased 

 yield to be obtained from good soil will amount to the value of 

 6s. 8d. In this connection it may be mentioned that all dairy 

 refuse, even the washing water, has great fertilising value in virtue 

 of the nitrogenous matter which it contains. The washing water 

 should therefore, wherever possible, be used for surface irrigation 

 on the fields instead of, as is sometimes done, run into ditches where 

 it will putrefy. In this case the milk sugar, or rather the lactic 

 acid formed therefrom, is a drawback, but as a rule the latter 

 will be neutralised by the large amounts of lime used in cleaning. 



1 English patent 4504, 1912. The patent covers continuous fermenta- 

 tions. 



2 C. Barthel and Sigurd Ehodin. Meddelande Nr. 57 fran Centralanstalten 

 for forsoksvasanet pa jordbruksoniradanet, 1912. 



