208 EXPERIMENT STATION RECORD. 



to 2.7 cc. Artificial honey gives either no precipitate or less than 0.5 cc. If 

 proteins have been added to artificial honey, differentiating tests, such as 

 Brautigam's, Ley's, and Fiehe's reactions, may be applied." 



Detection and determination of the protein substances of honey, E. Moreau 

 (Ann. Falsi/., 't {1911), No. 27, pp. S6-.'il). — A description of methods for the 

 qualitative and quantitative estimation of proteins in honey, which is accom- 

 panied by the results obtained for total and heat-coagulable proteins. It was 

 noted from the results that the proteins of honeys are very variable in amount 

 and nature, and furthermore there is an indication that a proteolytic ferment 

 is present in honey. 



Constituents of the apple, C. Thomae (Jour. Prakt. Chem., n. ser., SJi (1911), 

 No. 16-17, pp. 2Ji7, 2Jf8). — This is a preliminary study of the odoriferous sub- 

 stances in the peel of the apple. 



When apple peels were subjected to distillation with steam, and the distillate 

 (which had a pleasant apple odor) was extracted with ether, the solvent evap- 

 orated, and the residue obtained with absolute alcohol extracted, a crystalline 

 compound was found to remain. The filtrate from this compound when evap- 

 orated yielded a yellow oil having a pronounced apple-like odor. On rendering 

 the peels alkaline by pouring soda solution over them, and then extracting 

 with ether and evaporating off the solvent, there was left behind a colorless 

 pulverulent substance, which was soluble in hot alcohol, and after purifica- 

 tion had a melting point of over 200° C. and was odorless. This substance in 

 combination with the fat or resin present in the peel of the apple probably 

 prevents incipient drying of the fieshy part of the apple. 



The detection and role played by polyatomic phenols occurring' in apples 

 as glucosids, H. P. Bassett {Ahs. in Bcicnce, n. scr., 3'f (1911), No. 868, p. 

 22.'/). — Apples contain a glucosid which resembles phloridzin and an enzym 

 which hydrolyzes it and liberates a polyatomic phenol. This in turn is con- 

 verted into a phlobaphen by an oxidase. It is suggested that as this oxidase 

 reaction renders the fiuid germicidal it must have a protectiA'e action for the 

 fruit. 



Quantitative determination of starch sirups in fruit products, K. Beck 

 and P. Leiimann (Ztschr. U'ntcrsucJi. Nalu: u. Genussmfl., 21 (1911), No. 7, 

 pp. 393-J,05; ahs. in Chcm-. ZcntU., 1011, I, No. 22, p. 1611).— The insoluble 

 portion of the fruit products can be determined either by the Juckenack and 

 Prause procedure,'^ by one of the methods proposed for determining the extract 

 in wine (determination of the total dry substance and the invert extract), or 

 by a method in which a definite amount of the product is digested with a 

 definite weight of alcohol. For determining the rotation of the optically active 

 soluble substances the constants for dry substance of the soluble part and 

 starch sirup must be known. The specific rotation [a]p for the first named 

 can be taken as — 20°. 



The results of examining starch sirup for dry substance and the specific 

 rotation were found to agree well with the figures found in the literature. 

 The formulas involved are stated in detail, and the results of analyzing 51 

 fruit products to illustrate the above points are given. 



Electrolytic determination of copper in conserves, K. Lakus (Ztschr. Unter- 

 snch. Nahr. u. Genussmtl., 21 (1911), No. 11, pp. 662-66^; ais. in Ztschr. Angeu-. 

 Chem., 21f (1911), No. 31, p. 11/91).— K description of a method in which the 

 copper deposition is uniform and strongly adherent to the platinum dish. 



Vinegar, its examination and judging (Ztschr. Angew. Chem., 21/ (1911), 

 No. 31, pp. 11/82-11/85). — A discussion of the detection of formic acid in vinegar 



"Ztschr. Untersuch. Nahr. u. Genussmtl., 8 (1904), No. 1, pp. 26-36. 



