AGRICULTURAL CHEMISTRY ACiROTECHNY. 23 



"The superior value of the higher density media for the estimation of micro- 

 organisms in sugars is believed to be due to the injurious influences exercised 

 upon one class of these micro-organisms by the change from the density of the 

 film of moisture around the sugar crystals to the low density media. The 

 methylene blue reduction method is inapplicable to the quantitative estimation 

 of micro-organisms in sugars. The most favorable reaction for the culture 

 medium is neutrality with phenolphthalein as an indicator. The growth of the 

 micro-organisms of sugars upon high density media is slower than upon those 

 of low density. The basis of Smith's formula for the sucrose agar,« which has 

 been used for the determination of micro-organisms in sugars, has been proved 

 to be essentially correct." 



See also a i)revious note (E. S. R.. 25, p. 110). 



Progress made in the field of cocoa and chocolate manufacture in the 

 years 1905-1912, R. Bohme {Chem. Ztg., 37 (1913), Nos. 51, pp. 517-519; 53, 

 pp. 542, 5J/3; 56, pp. 574, 575). — This deals with the chemical, technical, and 

 legal aspects of the industry. 



On the protein substances of barley in the grain itself and during' the 

 brewing processes. — III, Transformation of the protein matters during 

 mashing, boiling of wort, and fermentation, H. Schjerning (Compt. Rend. 

 Lah. CarJsherg, 9 {1913), No. 4, pp. 237-396, fig. J).— This is a continuation of 

 the studies previously noted (E. S. R., 23, p. 412), and brings out the fact that 

 the transformation of protein takes place chiefly during germination and is 

 proportional in extent to the duration of the latter. On the other hand, the 

 more important changes taking place in the carbohydrates and mineral sub- 

 stances occur during the mashing process, the optimum temperature lying 

 around 70° C. The velocity or facility with which protein transformation takes 

 place, as measured by the author's precipitation method, is not in inverse ratio 

 to the total nitrogen content of the dry substances of the barley. 



The value of barley for malting purposes depends not only upon its behavior 

 during the steeping process but also on the length of time it requires to com- 

 plete the protein transformation during germination. A faulty transformation 

 of albumin and similar substances during germination can not be rectified by 

 the subsequent mashing process. 



The concentration of the hydrogen ions was not affected by the steeping, 

 germination, and mashing processes in themselves. " The measurements of the 

 numerical values of the different protein transformation processes by the pre- 

 cipitation method, and of the extent of peptid splitting through a formol titra- 

 tion, act as supplements, but can not replace each other. The protein ti'ans- 

 fo^mation processes mark the proteolysis down to the formation of the most 

 complex amin-amid compounds, while the peptid splitting particularly marks 

 the decomposition of the most complex into the less complex amin-amid com- 

 pounds." 



The remainder of the work deals with the influence of the mashing process, 

 i e.. fineness of the grist, concentration of mash, mashing temperature, duration 

 of initial mashing, duration of boiling, elutriation (sparging) of husks (grains), 

 and the salt effect ; the boiling of the wort, viz, duration of boiling, the propor- 

 tion of hops, effect of the hops upon the substances existing in the wort itself, 

 the tempeuature or pressure, wort concentration, oxygenation during boiling, and 

 the quality of the hops, etc.; and fermentation (primary and secondary). 



The thirty-first general meeting of the society of starch interests in 

 Germany, 1913, E. Parow {Chem. Ztg., 37 (1913), No. 34, pp. 3.'f5, 346).— A 

 report of the activity of the laboratories of this society. 



"Proc. Linn. Soc. N. S. Wales, 26 (1901), pt. 4, pp. 674-683. 



