RECENT WORK IN AGRICULTURAL SCIENCE. 



CHEMISTRY. 



The determination of citrate-soluble phosphoric acid in bone 

 meal, superphosphates, etc., O. Bottcher (Ghem. Ztg., 22 {1898),. 

 No. 21, pp. 201, 202). — Five grams of the substance is rubbed fine with 

 a dilate acid ammonium citrate solution (1 volume of the concentrated 

 solution mixed with 4 volumes of water), washed into a 500 cc. flask, 

 which is then filled to the mark with the dilute acid citrate solution at 

 the room temperature (about 17.5° C). The flask is then closed with 

 a rubber stopper and kept for 30 minutes in a rotating apparatus which 

 revolves 30 or 40 times per minute. The mixture is now filtered and 

 suitable portions of the liquid taken for the determination of phos- 

 phoric acid, either by the molybdate or the citrate method. — J. T. 



ANDERSON. 



A contribution to the determination of potash, J. Diamant 

 ( Ghem. Ztg., 22 (1898), No. 12, p. 99).— -The method proposed involves the 

 reduction of potassium-platinum chlorid by means of zinc dust, and 

 the volumetric determination of chlorin in the liquid residue. About 

 0.5 gm. of potassium-platinum chlorid (the amount taken of the potash 

 compound to be analyzed being such as to yield about that amount of 

 the double salt) is collected on a filter and washed in the usual way. 

 It is then dissolved in hot water in a 500 cc. flask and the volume made 

 to the mark with cold water. It is now shaken with about 1 gm. of 

 zinc dust, when reduction begins instantly. When the color disappears, 

 showing that reduction is complete, the liquid is filtered through a dry 

 filter, and 250 cc. of it is used for the volumetric determination of 

 chlorin. — J. t. Anderson. 



A new method of determining fat in feeding stuffs, meat, 

 feces, etc., L. Liebermann and S. Szekely (Arch. Physiol. [PJiiiger], 

 72 (1898), No. 7-8, pp. 360-366, fig. 1).— The author describes in detail 

 a method of determining fat as follows: Boil for half an hour 5 gm. of 

 substance with 30 cc. of 50 per cent potassium hydroxid solution (sp. 

 gr. 1.54), over a free flame, shaking frequently. This should be done 

 in a flask of suitable shape which when filled to about the middle of 

 the neck will contain about 290 cc, and has a mark at 240 cc. When 

 cool add 30 cc. of 90 to 94 per cent alcohol and warm for about 10 min- 

 utes, then cool and add carefully, in small portions, 100 cc. of 20 per 

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