AGEICULTUBAL CHEMISTRY AGROTECHNY. 807 



In regard to apple marmalade and jelly, H. Pellet {Monit. ScL, Jf. ser., 

 2It {1910), II, No. 828, pp. 777-78-^; ahs. in Ann. Falsif., 4 (1911), No. 29, p. 

 163). — The author criticizes the worlf of Chauvin (E, S. R., 23, p. 167) in regard 

 to the use of Clerget's method for determining sucrose, levulose, glucose, and 

 invert sugar (inverted by the acid present in the apple), and states that the 

 conclusions drawn by this author are diametrically opposed to the results 

 obtained by himself and others. 



He concludes that dextrin is not attacked by a 10 per cent solution of hydro- 

 chloric acid and thus has no influence upon the results obtained with tlie 

 Clerget test. Furthermore, a mixture consisting of 75 gm. of sugar and 5 gm. of 

 dextrin in 100 cc. of water acidified with tartaric acid will give exact results for 

 sugar, while dextrin is not affected when heated to 95° C. for 15 minutes or 

 at 100° C. for 15 minutes, nor when heated while exposed to the atmosphere. 

 Such a mixture shows a boiling ]ioint of 115° C. Prolonged heating of solu- 

 tions of this composition with 10 per cent hydrochloric acid at from 80 to 82° 

 C. for 3 hours showed a complete inversion of the dextrin. The plane of rota- 

 tion of the invert sugar turned to the right, but the reducing power did not 

 vary much from that in the solution in which tartaric acid was used. 



Experiments with yeast yielded the same results. 



Detection of fusel oil in brandy, E. Herzog (Ztschr. Unterstich. Nahr, u. 

 GcnussmtL, 21 (1911), No. 5, pp. 280-282).— The author points out that Hol- 

 lander's reaction (E. S. R., 23, p. 216) is due to the co-presence of furfui'ol with 

 the fusel oil in brandy. He considers it a furfurol reaction because no emerald- 

 green coloration could be obtained with an alcoholic solution of fusel oil. 

 Benzaldehyde, oil of fennel, and oil of cinnamon give a similar reaction with 

 Hollander's reagent. 



Determination of lactose in milk, Vitoux (Ann. Falsif., 3 (1910), No. 25, 

 pp. -'ill, Jil2). — The author points out that practically the same results can be 

 obtained by the French official and Deniges methods. The latter method is 

 preferre<l for milks preserved with potassium bichromate. Both methods are 

 given in detail. 



On the peroxydase of cows' milk and its detection by means of the para- 

 phenylendiamin test, E. Nicolas (Bui. Soc. Chim. France, Jf. ser., 9 (1911), 

 No. 6, pp. 266-269). — In this work it is pointed out that while precipitated and 

 boiled casein will give a reaction (blue coloration) with paraphenylendiamin 

 and hydrogen peroxid, it is the latter which first acts with the paraphenylen- 

 diamin, and that the casein only subsequently combines with it in order to 

 give the blue coloration. The reaction, furthermore, takes place only when 

 hydrogen peroxid and paraphenylendiamin are present in concentrated solu- 

 tions. In dilute solutions the reaction appears only when a little bran is 

 added. 



The above findings are contrary to those obtained by Bordas and Touplain 

 (E. S. R.. 23, p. 417). 



Refractometric milk examination, G. Ktjhn (Ztschr. TJntersuch. Nahr. u. 

 Gcmtssmtl., 20 (1910), No. 9, pp. 575-579). — The author points out the accuracy 

 with which water can be detected with the Ackermann method (E. S. R.. 25, 

 p. 207) using numerous samples of commercial milks and the corresponding 

 barn samples. In practically all instances conviction was obtained on the basis 

 of the refractometric test. 



In regard to the origin of ammonia in milk, L. Marcas and C. Huyge 



(ReiJ. Gen. Lait, 8 (1911), No. 21, pp. 487-^86).— The authors, using Trillat and 



Sauton's test (E. S. R., 17, p. 287), examined commercial milks in different 



parts of France in order to determine the frequency of the occurrence of am- 



17732°— No. 9—12 2 



