306 EXPERIMENT STATION RECORD. 



consists of precipitntiiif: 25 j;in. of sirup with H cc. of porchlorid of iron, col- 

 lecting tbo gum on tho tiannel tilter, dissolving it in fiftli-nornuil hyrtrochloric 

 acid and water, and rciu'ocipitatini? with 12 to 15 times its volunio of 95 per 

 cent alcohol. The precipitate is collected on a tareii filter, dried, and weighed. 

 The weight niultii)lied by 40 gives the amount of gum per liter of sirup. 



The determination of starch, Buisson {Bui. Assoc. Chim. Sucr. et Distill., 

 26 (1909), No. 10, pp. 980-983; ahs. in Rev. G6n. Chim., 11 (1909), No. 77. pp. 

 35S, So'/). — This is a modification of Baudry's method, in which 5.41 gm. of the 

 finely ground material is talcen. 25 cc. of a saturated solution of picric acid and 

 100 cc. of water added, and the mixture boiled for 45 minutes in a bath of cal- 

 cium chlorid. The fiask is then filled up to the 200 cc. mark and the solution 

 filtered and i)olarize(l in a 400 mm. tube. 



Determination of starch in barley, O. Neumann (Wchnschr. Bran., JC) 

 (1909), No. 25, pp. 306-309; ahs. in Ztschr. Angew. Chem., 22 (1909), No. 3Jh p. 

 169o). — A compilation of the various newer methods for the estimation of 

 starch in barley. 



The determination of phosphorus in foods, feces, and urine, F. W. Gill, 

 J. B. Peterson, and H. S. (Jkindley (I'roc. Anicr. *S'oc. Bioi. Chon., 1 (1909). 

 No. //, p. 159). — This is a comi)arative study of methods for total inorganic and 

 organic phosphorus determination in fiesh, etc. 



It was found that the magnesium nitrate, nitric acid, Kjeldahl, nitric and 

 hydrochloric acids, and direct ashing methods gave practically the same results. 

 It was further shown that barium nitrate in the presence of ammonium hy- 

 droxid, or barium hydroxid alone, precipitated from an aqueous extract of meat 

 containing no coagulable protein the same amount of inorganic phosphorus as 

 does the method of Hart and Andrews (E. S. R., 15, p. 42S). 



Taking economic factors into considei'ation, tests were made with the nitric- 

 hydrochloric acid digestion method, which was found to convert all the phos- 

 phorus into a form from which it can be precipitated as molybdate. Compai"a- 

 tive tests with urines of the uranium acetate solution (volumetric method) and 

 the nitric-hydrochloric acid method showed that the former gave somewhat 

 lower results. 



Method for the detection of small amounts of water in lard (Ztschr. 

 Untersuch. Nahr. u. Geimssmtl, 18 (1909), No. 7, Bcihigc, pp. 387-389). — This 

 is the official test used by the treasury department of the German Government. 



Ten gm. of fat is brought into a trani^parent glass tube !) cm. long and with 

 a capacity of 18 cc, which can be stoppered and in which a thermometer is in- 

 serted which dips into the fat. When the tube is heated to 70° C, if the fat is 

 clear the water content, it is concluded, is below 0.3 per cent. If it is cloudy 

 at 70° it is heated up to 95°, allowed to cool gradually, and the temperature 

 detei'mined at which cloudiness sets in. If this is found to be constant at over 

 75° the lard contains more than 0..3 per cent of water. 



The cholesterin content of eg'g's, H. Cappenberg (Chcm. Ztg., 33 (1909), 

 No. 112, p. 985). — The fact that lecithin is easily decomposed makes it an un- 

 certain constant for judging l)akery ]iroducts containing eggs, and the author 

 suggests employing the cholesterin content in its stead. A series of analyses 

 showed that the fatty egg oils contain an average of 3 per cent of cholesterin, 

 and therefore that eggs with an average content of 12 per cent of fat have 

 about 0.36 per cent cholesterin. 



A method for determining cholesterin is appended. 



Color reaction for gelatin, K. E. Liesegang (Ztschr, Chem. u. Indus. Kol- 

 loidc, 5 (1909), No. 5, p. 2^'i8). — If diffusion streams consisting of a 40 per cent 

 tricalcium phosphate and a 10 per cent copper chlorid solution are allowed to 



