408 EXPERIMENT STATION RECORD. 



(1911), No. 581, II. p. 223). — In white grapes 2 chromogenic substances are 

 present', one of which is precipitated with lead acetate. With hydrochloric acid 

 coloring matters can be obtained which are similar to cenocyanins. The conver- 

 sion of these substances into coloring matters, according to the author, is not 

 an oxidation process but is due to hydrolytic scission with the formation of a 

 reducing body. The residue obtained from the chromogenic substances contains 

 bodies which give a red coloration with alkali. 



Progress in the examination and judgement of foodstuffs and condiments 

 during the years 1909 and 1910, Utz (Osterr. Chem. Ztg., U {1911), Nos. 12, 

 pp. t. ',9-153; 13. pp. 1G5-1G7: 1',. pp. Ill, nS; 15. pp. 188-19.',).— This is a 

 retrospect of the more important advances made in this regard. 



The optical behavior of lactic acid in a meat preparation, E. Salkowski 

 (Hoppc-Seylcr's Ztschr. Vhysiol. Chem., 69 {1910), A"o. 6, pp. Iill-klS; ahs. in 

 Jour. Chem. Soe. [London], 100 {19hl), No. 579, I, p. 6). — While examining the 

 lactic acid contained in an American beef extract it was noted that after a time 

 the lactic acid passed over into the optically inactive form. The transforma- 

 tion was completed in one year. This change may be due to the presence in 

 the extract of a large quantity of potassium dihydrogen phosphate. 



The quantitative microscopic detection of ustilaginous spores (Tilletia 

 caries, etc.) in flour, bran, and cereals, G. Beedemann {Landw. Vers. Stat., 75 

 (1911), No. 1-2, pp. 135-151). — The existing methods for determining ustilagi- 

 nous spores in cereals are only applicable to whole grain and not to ground or 

 mill by-products. The author proposes the following method for this purpose: 



From 3 to 5 gm. of material is finely powdered so as to pass through a sieve 

 having meshes 0.3 sq. mm., and dried in a water oven. A small portion of the 

 powder is then placed upon a glass slide and mixed with a few drops of hydro- 

 chloric acid-chloral hydrate-glycerin mixture (10 parts of chloral hydrate, 

 5 parts of water, 5 parts of glycerin, and 3 parts of 25 per cent hydrochloric 

 acid, specific gravity 1.124), and heated to the boiling point on the slide. 



If the amount of spores in the cereal is not abnormal about 5 spores per 

 field (magnification 150 diameters) will be present. The mixture in this case 

 will serve directly for the quantitative determination. If, however, more 

 spores than this are present 1 part of the mixture is diluted with 9 parts of 

 rice starch in a porcelain mortar. Of this mixture from 5 to 8 mg. are care- 

 fully weighed off on a slide, mixed with from 3 to 4 drops of the hydrochloric 

 acid-chloral hydrate-glycerin mixture delivered from a capillary pipette, gently 

 warmed over a micro burner until a paste is formed, allowed to cool, and 

 covered with a 20 mm. cover glass without using pressure. The spores con- 

 tained in the entire preparation are counted (magnification 165) with the aid 

 of a searching table, and the results calculated to 10 mg. of sample. The 

 figures thus obtained are divided by what is considered the normal amount of 

 spores present in a good sample of cereal, viz, 450,000. 



Tests with the method are given. 



The colorimetric determination of copper in canned goods, H. Sergeb 

 (Chem. Ztg., 35 (1911), No. 102, p. 935 ) .—Although the author obtained very 

 satisfactory results with the Lakus electrolytic method (E. S. R., 2G, p. 208) 

 with conserves colored by copper sulphate, he was not entirely satisfied, 

 because of the time required for the execution of the process, and, furthermore, 

 the fact that when minimal amounts of copper were present the method left 

 much to be desired. Attempts were therefore made to use a colorimetric 

 method where small amounts of copper were in question. The results with 

 peas and spinach containing copper salts showed that the colorimetric method 

 when properly applied will yield good results. The objection made to the pro- 



