206 EXPERIMENT STATION RECORD. [Vol.40 



from 31 to 36 minutes. The age of the paste did not seem to affect the 

 determination. 



The determination of fat in cocoa, Kreis {Mitt. Lcbensm. Untersuch. u. TTjig., 

 Schicciz. Gsndhtmmt., 7 (1916), No. 6, pp. 815-819). — The method proposed is 

 as follows: 



A mixture of 1 gm. of cocoa with 20 cc. of a 1.5 per cent solution of hydro- 

 chloric acid is boiled gently for 15 minutes over a free flame. After cooling 

 to about 30° C, it is shaken with ether for 5 minutes and centrifuged for 

 15 minutes. After reading the volume of ether-fat solution, 25 cc. of it is 

 pipetted into a nickel dish, the ether evaporated, and the residue dried for 



10 minutes in a Soxhlet drying oven. 



Methods of determining the true sucrose content of molasses, T. van der 

 Linden (.1/ cded. Proefstat. Java-Suikcrindus., Chcm. Ser., Xo. 6 (1911), pp. 

 1249 1212; Irch. Suikerindus. Xcdaland. Indie, 25 (1911), Xo. SO. pp. 1249- 

 1212). — The newer acid, neutral, and special methods of determining the su- 

 crose content of molasses arc outlined, and experimental data are reported of 

 a comparative study of several of these methods. 



A new method for the determination of crude fiber in meal. YV. Hi clenherg 

 (Mitt. Lebenam. Untersuch, u. Hyg., Schxoeis, Otndhtaomt., 7 [1916), No. 6, pp. 

 291-302).— The following method is proposed as a substitute for the Kdnlg 

 method, previously noted (B. S. R., 10, p. 411), to obviate the necessity of 

 using glycerin : 



To 2.5 gm. of the substance is added from 10 to 15 <•<•. of 8 per cent alcoholic 

 potassium hydroxid, the mixture is healed for about five minutes on a water 

 bath at from 45 to 50° <'., 20 <c. of concentrated hydrochloric acid (sp. gr. L19) 

 is then added, and the heating continued with frequent shaking for half an 

 hour. The contents of the flask are filtered on an asbestos filter and washed 

 with from L!0 to 25 cc. of 25 per cent hydrochloric acid (2:1) until the titrate 

 is colorless. The residue is then washed with 200 CC of hot water, with hot 

 8 per cent sodium hydroxld until the filtrate is colorless, again with hot water, 

 with from 20 to 25 cc. of hot '.'0 per cent alcohol, and finally with from lit to 

 15 cc. of alcohol-ether mixture. The residue is transferred to a platinum 

 crucible, dried to constant weight, incinerated, and weighed, the loss in weight 

 on ignition being taken as ash-free crude fiber. 



Determination of urinary carbon, L. Bauzil (Jour. Phnrm. ct ('him., 1. 



11 (1918), No. 10. pp. 811-819). — The method described consists essentially of 

 the destruction of organic matter and liberation of carbon dioxid by chromic 

 and sulphuric acids, the transformation of carbon dioxid into barium carbonate 

 by barium hydroxid, and the alkalimetric determination of the barium 

 carbonate. 



Determination of total carbon in various biological products, A. RjENAUD 

 (Jour. 1'harm. ct Chi»i.. 1. set:, 18 (1918), No. 4. pp. 106-108).— The method, 

 which is similar to that of Bauzil (noted above) for the determination of car- 

 bon in urine, consists essentially in treating the substance to be analysed with 

 a sulphochromic acid oxidizing agent and absorbing the carbon dioxid and 

 chlorin set free by means of an ammoniacal solution of calcium chlorid. The 

 carbon dioxid is precipitated as calcium carbonate and determined volumetric- 

 ally after washing. 



The substitution of calcium chlorid by barium chlorid is considered to offer 

 certain advantages in that the precipitation of barium carbonate is rapid and 

 complete. On treating the precipitate thus obtained with an excess of sul- 

 phuric acid, barium sulphate is precipitated which is washed, dried, and 

 weighed. 



