AGRICULTURAL CHEMISTRY AGROTECHNY. 413 



Jour. Chem. Soc. [London], 102 {1912), No. 601, II, p. 1110).— It the green 

 shell of an unripe walnut is immersed in a copper acetate solution, crystalline 

 needles of the copper-juglone compound begin to form immediately in the cells, 

 while the hydrojuglone. which exudes from the cells, forms a precipitate. " If the 

 section is now washed with water and treateil with chloral hydrate solution the 

 masses of crystals which at first api)eared black become red. On subjecting a 

 section of the tissue to the action of nitric acid vapors, black crystals (juglonic 

 acid?) form in the cells. A further test consists in treating a section on a 

 microscope slide with a drop of anilin and placing a cover glass over it; after 

 the lapse of a few minutes, reddish-brown crystals form in the anilin near the 

 edges of the cover glass. The sections may be also subjected to micro-sub- 

 limation and the sublimate tested wnth the above mentioned reagents." 



The crystals give a red coloration with sulphuric acid. re<ldish with dilute 

 potassium hydroxid, a violet coagulum forming at the edge of the drop, apd 

 violet-blue with ammonia gas. 



Further researches on the testing of oiled paprika, A. de Sigmond and 

 M. VuK {Kis6rlet. Kozlem., 15 {1912), No. 2, pp. 2S9-252).— Continuing the 

 work previously noted (E. S. 11.. 27, p. 715), the authors have tried a method 

 for detecting added oil in paprika which consists in leaching the surface oil 

 with water and determining the ether extract in the resulting solution. The 

 method gave unsatisfactory results when it was used for both pure and oiled 

 goods. The iodin numbers of the oils and natural and oiled goods were unreliable. 



Some other experiments showed that various solvents extract different quan- 

 tities of substances from the pericarp of the paprika fruit, e. g., ethyl ether 5 

 per cent, ethyl alcohol 18.9 per cent, and methyl alcohol 34.3 per cent. The 

 latter results were obtained by macerating 3 gm. of paprika with 100 cc. of the 

 solvent for 48 hours at room temperature of from 20 to 22° C. 



Characteristic color reaction of soy-bean oil, L. Settimj {Abs. in Jour. 

 Chcm. Soc. [Lo7idon], 102 {1912), No. 601, II, p. 1108).— The reaction is as 

 follows : 



To 5 cc. of oil in 2 cc. of chloroform add 3 cc. of a 2 per cent aqueous solu- 

 tion of uranium nitrate, and shake. If the sample is soy-bean oil, a lemon- 

 yellow-colored emulsion is produced. Some samples of olive oil gave a faint 

 yellow emulsion, but all other oils tried showed white. Soy-bean oil gave the 

 remaining usual reactions for seed oils while oUve oil did not. 



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

 NacJnrci.'i von. Sdialcn iiit Knkao nnd in seiiicii Priipaniten. Diss., Ilerzogl. 

 Tech. HochscJi. Carolo Wilhelmina, Braunschweig, 1911, pp. 97). — In addition 

 to what has been previously reported (E. S. R., 29, p. 205), it is shown that 

 Filsinger's and Drawe's elutriation methods can be used for detecting additions 

 of cacao shells from 7.5 per cent up in normal cocoa which contains 30 per cent 

 of fat and water, providing the sample under examination is finely powdered 

 and the appropriate correction factors are applied in the calculations. 



The Matthes and Miiller modification of Konig's method for crude fiber is not 

 deemed of value for practical conditions, as it will not detect less than 27.5 per 

 cent of shell in normal cocoa. The pentosan detection according to the Tollens 

 and Krober method is also imperfect as it will note only 25 per cent or upwards 

 of shells. The iodin value of the cacao fat gives no clue so far as adulteration 

 is concerned. 



Numerous analyses of raw and prepared materials are included. 



The relative value of indicators in the acid titration of wines, F. Maree 

 (7?rr. G(:-ti. CJiim., 15 {1912), No. 13. pp. 2-^2, 243: ahs. in Jour. Chem. Soc. 

 [London'\, 102 {1912), No. 601, II, p. 1106).— As an indicator in the analysis of 



