616 EXPERIMENT STATION RECORD. [Vol.35 



The physiolog^y of souring of pure and watered milk, F. Reiss (Ztschr. 

 Untersuch. Nahr. u. Genussmtl., 31 {1916), No. 2, pp. Itl-Jf5). — From experi- 

 mental data submitted it is concluded that within rather wide limits of milk 

 watering in the course of lactic acid fermentation amounts of lactose are 

 fermented which are inversely proportional to the degree of watering. While 

 more conclusive evidence is necessary to answer the question whether the 

 degree of aciditj^ can be definitely used as an index of the amount of water, 

 it is deemed certain that from the degree of acidity of sour milk it can safely 

 be determined whether or not the milk was originally watered. 



The gravimetric determination of reducing sugars in cane products, G. P. 

 Meade and J. B. Harris {Jour. Indus, and Engin. Chem., 8 {1916), No. 6, pp. 

 504-509). — In clarifying the sugar solutions the authors found that different 

 results were obtained by the use of varying amounts of neutral lead acetate 

 solution. 



" Carbonate, sulphates, and oxalates are not interchangeable as deleading 

 agents, oxalates giving results from 4 to b per cent higher on the weight of 

 copper than where either of the others is used. Kieselguhr only, without the 

 use of lead or other reagent, gives a clear filtrate, both with final molasses 

 and raw sugar, and the solution offers no mechanical difiiculty in the precipita- 

 tion and collection of the copper precipitate. Without lead the results are 

 slightly lower than where lead and oxalate are used." 



Results obtained by weighing the cuprous oxid were about 5 per cent higher 

 on the weight of copper than those obtained by igniting and weighing as cupric 

 oxid. Volumetric iodid determinations of the copper checked the cupric oxid 

 results. 



It is indicated that, " under strict specifications as to the quantity and class 

 of reagents, any method for the preparation of the solution for analysis will 

 give results which check within themselves." 



The determination of the gelatinizing temperature of the starches from 

 the grain sorghums by means of a thermo-slide, C. K. Francis and O. C. 

 Smith {Jour. Indus. aiuL Engin. Chem., 8 {1916), No. 6, pp. 509-511, figs. 2). — 

 Thi« material has been previously noted from another source (E. S. R., 35, 

 p. 108). 



A colorimetric method for the estimation of free formaldehyde and hexa- 

 methylenamin, R. J. Collins and P. J. Hanzlik {Jour. Biol. Chem., 25 {1916), 

 No. 2, pp. 231-237). — A colorimetric method in which the phloroglucinol reagent 

 (0.1 gm. phloroglucinol in 10 cc. 10 per cent sodium hydroxid) is used is 

 described. 



Permanent color standards are prepared from mixtures of Congo red and 

 methyl orange. Standard mixtures for concentrations of formaldehyde between 

 1 : 1,000,000 and 1 : 20,000 have been determined and are submitted. It is in- 

 dicated that the procedure described is more accurate than the Romijn, the 

 United States Pharmacopoeia method, and the hydroxid pressure method. It 

 is directly applicable for the determination of free formaldehyde in urine. 



[Report of the fermentation and bacteriological section], H. MiJLLER- 

 Thuegau and A. Osterwalder {Landiv. Jahrb. Schtcciz, 29 {1915), No. 5, pp. 

 537-568). — Experiments on the value of washing the fruit preliminary to press- 

 ing demonstrated that the washing did not yield a purer fermentation or a 

 more stable product. In the reduction of the acidity of wines, partial neutral- 

 ization with calcium carbonate and further reduction to any degree of acidity 

 desired by the action of Bacillus gracilis at various temperatures was found 

 to yield satisfactory results. 



From results obtained in connection with studies on the influence of sul- 

 phurous acid on fermentation processes in wines and fruit juices, it is indi- 



