AGRICULTUBAL CHEMISTRY AGROTECHNY. 205 



The purification of the acetates is based on a method devised by H. Matthes 

 and W. Heintz ", which consists of treating the acetates with 80 per cent 

 alcohol. The melting point of the acetates is finally determined. Cholesterol 

 acetate has a lower melting point than phytosterol acetate. 



The detection of shells in cacao and its preparations, C. Ulrich {Arch. 

 Pharm., 249 {1911), No. 7, pp. 52^-597; ais. in Chem. Abs., 6 {1912). No. IS, 

 p. 1816). — The methods now in use for determining the cacao shells in cacao 

 preparations can only be employed where 80 per cent or more of shells are 

 present. The author suggests a method which consists of extracting the prepa- 

 ration with a 50 per cent solution of acetic acid and precipitating with ferric 

 chlorid. This will show the presence of 10 per cent or more of shells devoid 

 of coloring matter. 



Examination of the precipitate produced by basic lead acetate in wine. — 

 Pentose and methyl pentose determination in grapes and wines, T. von Fel- 

 i.ENBERG {Mitt. Leliensm. Untcrsiich. u. Byg. Schweiz. Gsndhtsamt., 3 {1912), 

 No. 5, pp. 213-227, figs. 2). — If a wine is neutralized with calcium cnrbonate 

 and treated with lead acetate, filtered, and the filtrate treated with basic 

 lead acetate, or better, with basic lead nitrate, a precipitate is obtained which 

 consists of succinic acid, probably some sulphurous acid, inosit, pectin, pento- 

 san, methyl pentosan, and in red wines a trace of coloring matter. By deter- 

 mining the precipitate by the method described, artificial or dry berry wines 

 give abnormally low results. 



Grapes contain pentoses and methyl pentoses in a fre^j state which are in 

 part precipitable by basic lead nitrate. These are probably present as pento- 

 sans and methyl pentosans. Grape juice contains a large percentage of methyl 

 pentose while the dregs, hulls, seeds, and stems have a higher pentose content. 

 The dry wines of commex'ce contain very little pentose and methyl pentose. 

 Wines made from these dregs are characterized by having a different ratio of 

 sugars, i. e., pentose and methyl pentose, than the natural wines. 



The biological detection of poisonous castor bean constituents in feeding 

 stufEs, Kranich {Ztschr. Veterindrk., 2/f {1912), No. 10, pp. 455-464; abs. in 

 Berlin. Ticrdrztl. Wchnschr., 28 {1912), No. 48, p. 8.9/,).— Meissner's and 

 Mooser's findings (E. S. R., 22, pi. 81; 25, p. 683; 26, p. 209) in regard to this 

 subject are discussed but it is deemed necessary to have a much simpler method 

 for this purjiose. The method which is recommended is as follows : 



Two gm. of the feeding stuff is mixed with 40 cc. of glycerin, placed for 10 

 minutes in a water bath at 50° G., and shaken several times during the inter- 

 val. The mixture is expressed in a Mull filter 4 times, and the turbid fluid 

 which is obtained (about 35 cc), is mixed with 350 cc. of a mixture consisting 

 of equal parts of alcohol and ether. The mixture is allowed to stand for one- 

 qunrter of an hour to allow the precipitate to settle; the supernatant fluid 

 then poured off, the precipitate collected on a small folded filter, and washed 

 with alcohol and then with ether. The residue is allowed to dry in the air, 

 which takes about 15 minutes, and with the filter is then brought into a Petri 

 dish, 10 cc. of a 10 per cant sodium chlorid solution having a temperature of 

 50° C. poured over it, and the mixture filtered through an asbestos filter. One 

 cc. of the clear filtrate obtained is placed in an Uhlenhut test glass and a layer 

 of 0.1 cc. antiserum added in the usual manner. A reaction is obtained in 

 from 10 to 20 minutes. 



Detection of particles of castor seeds in feeding' stuffs, K. Bierbaum 

 {Ztschr. InfeMionskrayik. u. Hyg. Eaustiere, 12 {1912). No. 4, pp. 351-371). — 

 For the detection of nonnoisonous castor beans in feeding stuffs the comple- 



•Arch. Pharm., 247 (1909), No. 3, pp. 161-175. 



