1918] AGRICULTURAL CHEMISTRY AGROTECHNY. 113 



the high results obtained by the direct titration procedure, the casein was found 

 to be apparently responsible to the largest extent. 



The analytical data are submitted in tubular form. 



The influence of rafiinose of beet molasses on the exact polarization before 

 and after inversion by acid or invertase, H. Pellet {Bui. Assoc. Chim. Sucr. 

 et Distill., 35 {1916), No. 4-6, pp. 112-117).— Data are submitted which show 

 the effect of rafhnose on the determination of sucrose in beet molasses by in- 

 version. 



An increased polarization was observed whether the inversion was brought 

 about by means of acid or invertase. In the determination of sucrose in beet 

 molasses the quantity of rafBnose present must be deducted from the result 

 obtained by direct polarization to obtain the exact amount of sucrose present. 



Some tabular data showing the difference in polarization in the presence of 

 varying amounts of rafFmose are submitted. 



Pentose content of beet molasses, H. Pellet {Bui. Assoc. Chim. Sucr. et 

 Distill., 35 {1916), No. 4-6, pp. 117-121).— This is a general discussion, together 

 with the description of a procedure for determining pentoses in beet molasses. 



Methods for approximating' the relative toxicity of cottonseed products, 

 F. E. Caeeuth {Jour. Biol. Chem., 32 {1917), No. 1, pp. 87-90).— The author, at 

 the North Carolina Experiment Station, notes that on cooking cotton seed with 

 moist heat, as is done In the hot pressing processes preparatory to expressing 

 the oil, the glands containing gossypol are disintegrated and the substance is 

 spread over the surface of the seed tissue and apparently undergoes a change 

 which is assumed to be a partial oxidation. The change takes place very quickly 

 under suitable conditions, so that^ome meals which have been cooked only 20 

 to 30 minutes are not markedly toxic for rats. The changed gossypol is no longer 

 soluble in ether and oil, possibly because it is in some way chemically combined 

 with some constituent of the meal, probably the protein. Its presence can be 

 demonstrated, however, in ether-extracted cottonseed meal by treating with hot 

 alcoholic potash. The supernatant liquid contains the substance, which, like 

 gossypol, soon oxidizes with the production of a beautiful blue color. This sub- 

 stance is much less toxic than the original gossypol. The author has termed 

 this less toxic and soluble form " D " gossypol. 



For determining the presence of the highly toxic gossypol the following test Is 

 outlined : A very small amount of the meal is sprinkled on a glass slide and 

 touched with a drop of concentrated sulphuric acid and the material observed 

 immediately through the low power of the microscope. The presence of the toxic 

 unchanged gossypol is indicated by numerous red areas which appear where the 

 acid touches the more or less ruptured cells. Thoroughly cooked meals and 

 cottonseed flour are indicated as showing very few and very small red areas. 

 A relatively large number of red areas are, however, observed in meals cooked 

 with Insufficient moisture or for too short a time. 



For the quantitative determination of gossypol present in cottonseed meal, 

 auilin has been found to be a suitable precipitant of the material from an ether 

 extract. In the procedure 200 gm. or more of cottonseed meal is extracted 

 for two to three hours with ether, so as to yield from 5 to 10 gm. of oil. The 

 meal may be percolated or shaken with ether in a flask. The extract is evap- 

 orated to a small volume, filtered, and anil in (about 10 per cent of the weight 

 of the extract) added, and the mixture warmed on the water bath, set aside, 

 and allowed to stand for some time. If gossypol is present, a yellow micro- 

 crystalline precipitate of the anilin compound results. This substance appears 

 to be the dianiUn salt and is indicated as having the formula C3oH2s03.2CgH5NHi. 

 In case a sufficient amount of the precipitate is obtained it may be filtered 

 through a tared Gooch crucible, washed with a mixture of ether and petroleum 



