AGRICULTURAL CHEMISTRY AGROTECHNY. 209 



essence and the examination and judging of vinegar, by Messrs. Schnlimactier, 

 Frohlich, Rotlienbacb, Zuclier, Neufeld, Kerp, Bomer, Mooskopf, and Rnpp, at 

 the general meeting of the Association of German Food Chemists held at 

 Dresden. 



Pyridin in vinegar, H. Fincke (Ztschr. Untersuch. Nahr. u. Gennssmtl., 21 

 (1911), Xo. 11. pp. 655-658; aJ)s. in Ztschr. Augew. Chcm., 2J, {1911), No. 31, 

 p. 1491). — Since the brandy tax law went into effect in Germany vinegar in 

 many instances has been prepared from alcohol denatured with pyridin. 



For detecting the pyridin the author recommends treating 500 cc. of vinegar 

 with 10 cc. of 25 per cent sulphuric acid, evaporating the mixture to a bulk of 

 from 20 to 50 cc, and making it alkaline. The pyridin is then distilled into an 

 excess of hydrochloric acid solution, the distillate I'endered alkaline, sodium 

 hypobromite solution added until the fluid remains yellow in color, and 50 cc. 

 of the fluid distilled into from 10 to 30 cc. of decinormal hydrochloric acid solu- 

 tion. The excess of acid is titrated back with decinormal alkali solution, using 

 methyl orange as the indicator. 



The judging of brandies, A. Juckenack (Ztschr. Angew. Chem., 2^ (1911), 

 No. 31, pp. 1^77-1^79). — In this discussion are included cognac, rum, arrak, 

 fruit brandies (raspberry, apple, etc.), corn brandy, bitters, cordials, and mis- 

 cellaneous brandies. 



The estimation of soft resins in hops, R. H. Carter (Jour. Southeast. Agr. 

 Col. Wi/e, 1910, No. 19, pp. 375-385, pis. 2).— The object of this work was to de- 

 termine the relative amounts of soft resins present in English and German 

 varieties of hops grown at Wye, England, German varieties grown in Germany, 

 and American varieties grown in America. 



The percentage of resins in 13 samples of English hops of unknown parentage 

 was found to vary between 8.36 and 13.95, average 10.41 ; 13 seedlings of known 

 parentage, between 9.62 and 11.53, average 10.69; 9 German varieties of hops 

 grown in England, between 10.77 and 13.63, average 11.97; 5 English varieties, 

 between 10.6 and 13.7, average 11.94; 1 German variety grown in Bavaria, 

 17.08; and 4 American varieties grown in America, between 13.34 and 16.82, 

 average 15.12. 



The detection of castor-bean constituents in feeding stuffs, W. Mooser 

 (Landw. Vers. Stat., 75 (1911), No. 1-2, pp. 107-13^) .—This is an investiga- 

 tion as to the value of the precipitation test for detecting castor-oil seeds in 

 feeding stuffs. 



Rice-feed meal, sesame meal, and peanut meal free from ricinus, when treated 

 and injected into animals according to Miessuer's specifications (E. S. R., 22, 

 p. 81), were found to give a reaction indicating the presence of castor-oil seeds. 

 When normal serum was substituted for the specific serum in Miessner's proce- 

 dure cotton-seed meal, linseed meal, and rice-feed meal, all in a concentration 

 of 4 per cent, were found to give a positive reaction, but when the amount was 

 reduced to 1 per cent it was negative. Rice-feed meal gave the most positive 

 reaction. Normal serum with a 4 per cent concentration of ricinus also acted 

 as a specific serum. 



The author, assuming that some of the toxic principles are very soluble in 

 alcohol (arachin, for example, from peanut cake) and that riciu is only slightly 

 so, has elaborated a method for detecting castor-oil seeds based on this prin- 

 ciple. With the new method he believes that the concentration of the solution 

 and the time of exposure to the antiserum will be of no moment when seeking 

 to detect the above impurities in feeds. 



The effect upon the reaction of heating castor-oil seed cake is also considered. 



General considerations in regard to the microscopic analysis of feed cakes, 

 L. Palmans (Ann. GemUoux, 21 (1911), No. 4, pp. 184-200, figs. 12).— This is 



