502 EXPEEIMENT STATION KECOKD. 



from warm potassium hydroxid solution aud tlie latter by acidifying witli con- 

 centrated sulpburic acid. 



It was found tliat pure natural waters contain no protein ammonia, tlae limit 

 for a drinking water being set at 0.1 mg. per liter. 



Oxidation of carbohydrates and related substances by means of potassium 

 persulphate, J. K. Wood and Nellie Walkee {Jour. Cliem. Soc. [London], 105 

 (1914), No. 61S, pp. 1131-1140, fig. 1; abs. in Jour. 8oc. Chem. Indus., 33 (1914), 

 No. 10, p. 56i).— Aldoses may be almost quantitatively oxidized with potassium 

 persulphate in the cold and the process may be accelerated by the addition of 

 small quantities of silver sulphate. Galactose, arabinose, and xylose are oxi- 

 dized at about the same rate, polyhydric alcohols and dextrose more slowly, 

 while ketoses and disaccharids are attacked somewhat more rapidly than the 

 aldoses. 



Analytical work, P. L. Gile and J. O. Cakkero (Porto Rico Sta. Rpt. 1914, 

 p. 13). — ^A comparison of the potassium sulphocyanate colorimetric method for 

 iron with the permanganate method indicated that the former was preferable 

 for the determination of the small amounts of iron contained in most plant 

 substances. 



Determination of eggs in food pastes, L. Farcy (Ann. Falsif., 7 (1914), No. 

 66, pp. 183-187). — The soluble nitrogenous substances in food pastes were esti- 

 mated before and after boiling, as suggested by Rousseaux and Sirot (E. S. R, 

 31, p. 809). The purpose was to determine whether or not eggs had been used 

 in the goods under examination. 



The ferments of honey, F. Gothe (Ztschr. Untersuch. Nahr. u. Genussmtl., 

 28 (1914), No. 6, pp. 273-286, fig. 1; abs. in Ztschr. Angew. Chem., 27 (1914), 

 No. 99, Referatenteil, p. 700).— Lactase, proteases (peptic and tryptic), and 

 lipase could not be detected in honey. Inulase is probably present. Invertase 

 in honey is of both animal and vegetable origin, and in genuine bee honey its 

 amount is greater than in feeding honey. It is destroyed at 60° C. and has 

 its optimum of activity at 40°. Catalase and diastase are not present in the 

 same proportion in honey. By filtering honey a marked reduction of catalytic 

 power occurs, and when much impurity is present in honey it is evidenced 

 by a high catalase figure. Honey catalase is markedly affected by heating for 

 one hour at 60° C. (undiluted honey at 70°). 



Experimental studies on honey diastase activity as well as the judgment 

 of honey by its diastase content, F. Gothe (Ztschr. TJntersuch. Nahr. u. 

 Genussmtl., 28 (1914), No. 6, pp. 286-321, fig. 1; abs. in Ztschr. Angew. Chem., 

 27 (1914), No. 99, Referatenteil, pp. 700, 701). — Honey diastase is of both animal 

 and vegetable origin. Its quantitative estimation enables an estimate of the 

 value of a honey. A high diastase figure indicates absolutely pure honey. If 

 a medium figure is obtained. Fiehe's test, the precipitation test, and other 

 tests should be made to exclude the suspicion of adulteration. A low diastase 

 figure indicates a low-grade product which has been either overheated or adul- 

 terated. Heating undiluted honey for one hour at from 85 to 90° C. destroys 

 the diastase. Diluted honey loses its activity at 70°. 



Estimation of chlorin ions in honey, F. E. Nottbohm (Ztschr. Untersuch. 

 Nahr. u. Genussmtl., 28 (1914), No. 5, pp. 255-259; abs. in Ztschr. Angew. Chem., 

 27 (1914), No. 99, Referatenteil, p. 700).— By directly ashing honey more than 

 one-half of the chlorin is lost. This may be prevented, especially in honey high 

 in chlorin, by adding bicarbonate of soda. 



About the preservation of milk samples for examination purposes, J. Till- 

 MANs, A. Splittgerber, and H. Eiffart (Ztschr. Untersuch. Nahr. u. Genussmtl., 

 27 (1914), No. 12, pp. 893-901). — Mercuric chlorid in a concentration of from 

 0.04 to 0.03 per cent conserved milk samples for 120 hours. Samples so pre- 



