AGEICULTUEAL CHEMTSTEY AGEOTECHNY. 611 



and estimating the dextrose formed; (b) weighing the starch isolated accord- 

 ing to Mayrhofer; (c) saccharifying the starch isolated according to Mayrhofer, 

 and estimating the dextrose formed; and (d) estimating colorimetrically the 

 starch in the solution. 



After pointing out the various errors in the above methods, the author 

 recommends the following, though not as absolutely correct : Five gm. of mus- 

 tard are heated with 50 cc. of an 8 per cent alcoholic potassium hydrate solu- 

 tion in a flask connected with a reflux condenser and on a water bath for one 

 hour. The solution is diluted with 50 cc. of a 50 per cent solution of alcohol, 

 filtered hot through a Gooch crucible, and the residue in the crucible washed 

 with 50 per cent alcohol. The contents of the crucible are then brought back 

 into the extracting flask and extracted for one hour with 50 cc. of an aqueous 

 normal solution of potassium hydrate. The solution is brought up to a bulk 

 of 250 cc, and filtered through asbestos. To 50 cc. of the filtrate 50 cc. of 95 

 per cent alcohol is added, the mixture allowed to stand over night, then centri- 

 fuged, and the supernatant clear fluid passed through a Gooch crucible. After 

 this the residue is brought upon the Gooch filter and washed with 95 per cent 

 alcohol (by volume) and ether, dried to constant weight, and the weight re- 

 corded. The contents of the crucible are then ashed. 



The results are reported in percentages of ash and water-free starch on the 

 basis of dry substance. The author recommends applying a correction of 3 

 per cent for apparent starch. 



On the determination of aldehydes in distilled liquors, M. Vivencio del 

 RosAKio (Philippine Jmir. ScL, A. Chem. and Oeol. Sci., 5 (1910), No. 1, pp. 

 29-32). — ^As the official method for aldehyde in distilled liquors did not yield 

 satisfactory results, particularly in a tropical climate, the author modified the 

 Ripper method (E. S. R., 13, p. 524), with which more accurate results could 

 be obtained. 



The detection and determination of manganese in wines, Dumitrescou and 

 E. NicoLAU (Ann. Fctlsif., 3 (1910), No. 2^, pp. 407-JflO) .—White, red, and 

 dark red wines contain manganese as a natural constituent. The amount is 

 very variable and is always directly dependent upon the amount present in the 

 soil in which the grapes are grown. The manganese can be determined with 

 ammonium persulphate by oxidizing it to permanganate (E. S. R., 24, p. 211). 



Identification of food colors, H. M. Loomis (U. 8. Dept. Agr., Bur. Chem. 

 Circ. 63, pp. 69). — This is a tentative report on certain colors, and has to do 

 with their solubility and extraction and the color reactions of dyed fiber and 

 of aqueous and sulphuric acid solutions of colors. It is virtually a revised 

 edition, with some additions to bring it up to date, of Circular 25 (E. S. R., 17, 

 p. 788) and Circular 35 (E. S. R., 19, p. 306). 



Unification of analytical methods for the sugar industry in Germany 

 (Bui. Asf<oc. Chim. Sucr. ct DistiU., 2S (1910), No. J,, pp. 239-25J,; Ztschr. Ver. 

 Deut. Zuckerindus., 1910, No. 657, II, pp. 1004-1028) .—A detailed description 

 of the proposed methods. 



Method for determining saccharose polarimetrically and directly and in 

 the presence of reducing sugars, P. Lemeland (Jour. Pharm. et Chim., 7. ser., 

 2 (1910), No. 7, pp. 298-30S). — The method is based on the use of manganese 

 dioxid, hydrogen peroxid, and sodium hydrate for breaking down the reduc- 

 ing sugars in the presence of saccharose. 



About the use of the refractometer for the analysis of the products of 

 the sugar cane, F. Zeeban (Rev. Indufi. y Agr. Tucumdn [Argentina'], 1 (1910), 

 No. 2, pp. 33-36). — ^A discussion in regard to the use of the refractometer in 

 sugar analysis. 



