AGRICULTURAL CHEMISTRY — AGROTECHNY. 705 



obtained by the diffoivnt methods of inversion of siif;ar it was found that yeast 

 invertase did not produce products which give this reaction. When imre honey 

 was heated to 120° C. or heated for 1 hour at 100°, the Fiehe reaction was 

 itbtained. Pure honey heated at 00° for 2 hours gave a very slight reaction, 

 though pronounced. The reaction is ])robably produced by the formation of 

 /3-Oxy-S-methyl-fnrfurol. Attention is drawn to the fact that during tlie pro- 

 duction of chirified honey long heating is avoided as it tends to diminish the 

 quality of the article, but that it is possible to distinguish the difference 

 between a honey which has been overheated and one which is adulterated. 



Fiehe's reaction and that of Ley and Jag-erschniid, W. Bremer and F. Spon- 

 NAGEL (Zfsvhr. Uiitcrsucli. Xalir. ii. dciiKssinil.. 11' (1909), No. 11, pp. 66-'i- 

 6'6'7). — The authors obtained Fiehe's reaction with honey of undoubted purity. 

 In some instances it was obtained in the cold, while v.ith others it was apparent 

 only after heating In the water bath. It is also reported that a honey which 

 was declared to be artificial gave Fiehe's reaction only after heating for some 

 time in the water bath. With Ley and Jiigerschmid's method only 7 out of 9 

 natural honeys could be identified. The reaction, therefore, is not deemed alto- 

 gether reliable. 



The detection of mineral acids in vinegar, F. Utz (Ostcrr. Clictn.. Ztg., 11 

 (1908), No. 2Jf, pp. 326-328; aM. in Ztsrhr. Analyt. Chem., /,8 (1909), No. 6, 

 p. 389). — Fiehe's invert sugar reaction (E. S. R., 20, p. 612) was used, 4 to 5 

 gm. of cane sugar in 10 cc. of the vinegar being inverted in the water bath, the 

 solution cooled, and extracted 2 or 3 times with ether, the ethereal extract evap- 

 orated, and the residue treated with resorcin-hydrochloric acid. Even with very 

 small amounts of mineral acid present a rose-red color appears which rapidly 

 changes to a cherry red. 



The detection of inosit in natural wines, G. Perrin (Aim. Chini. Anahjt., l.'f 

 (1909), No. 5. pp. 182, 183; «7>.s. in Analyst, 3Jt (1909). No. J/OO, p. 32.',).— To 

 200 cc. of wine are added 20 cc. of basic lead acetate and a few drops of an 

 alcoholic solution of tannin. The filtrate is freed from lead with hydrogen 

 sulphid, decolorized with charcoal, and concentrated to a bulk of 200 cc. on the 

 water bath. Two drops of this concentrated solution are heated on a platinum 

 foil with 1 drop of a 10 per cent solution of silver nitrate and finally cautiously 

 igLited. Inosit gives a red-violet coloration which disappears on cooling. 

 Two more drops are then heated on another platinum foil witli 1 drop of nitric 

 acid, ignited as before, the residue treated with 1 drop of ammonia, and again 

 evaporated. A color less red than that obtained with silver nitrate indicates 

 that the wine contains inosit. 



The presence of inosit as a characteristic of natural wines, O. Meill^re 

 (Jour. Pharm. et Chim., 0. scr., 30 i 1909). No. 6. pp. ^.'/7-2-'/9).— The author con- 

 cludes that inosit is normally present in natural wine and discusses this ques- 

 tion. The estimation of inosit is discussed. 



Wote on a method to distinguish wines made from red or white grapes 

 (Ann. FulHtf., 1 (1908), No. 2, p. 83). — The sulphuric acid reaction is not suffi- 

 cient to determine whether a wine is made from white or red grajies. 



The analysis of alcohols and brandies, Mastbaum (Ahs. in Clicm. Ztg., 33 

 (1909), No. 69, p. 626). — It is slated that in the determination of aldehydes 

 the methods commonly employed are either colorimetric or volumetric. The 

 colorimetric methods are those of (Jaymi, Barbet, Jandrier and others. The 

 higher alcohols are estimated chiefly by 3 methods, those of Saville-CJirard, 

 Pocsc-Stufzer-Sell. and Marcpiardt-.MIen-Schidrowitz. 



Detection of methyl alcohol in ethyl alcohol, A. Vorisek {Join: .S'or. Chem. 

 Indu.s.. 28 (1909), No. 15, pp. 823-82'), ji<j. I). — As the bichromate-suli)huric 

 acid test often yields methylal and formaldehyde and sometimes oxidizes the 



