106 EXPERIMENT STATION RECORD. 



removed with a Ba])cock pipette and placed in a beaker. A tablet specially prepared 

 and containing a definite amount of nitrate of silver is dissolved in 50 cc. of cold 

 water. The solution containing an aliquot portion of the salt of the butter is then 

 carefully titrated with the nitrate of silver solution, using potassium bichromate as 

 an indicator. The number of cubic centimeters of the tablet solution used to pro- 

 duce a permanent brick-red color indicates the number of tenths per cent of salt 

 contained in the butter. Thus, 10 cc. of the silver nitrate solution indicates 1 per 

 cent of salt. The author states that he is able to bring variations within | of 1 per 

 cent of the standard desired. By employing this method the amount of salt in 

 butter can be more easily controlled and a more uniform i)ruduct produced. 



Determination of cocoanut oil in butter and in oleomargarine, J. Wauters 

 {Bui. Assoc. Beige Chim., 15 {1901), Xu. 1, pp. 25-28). — A distinction is found by 

 determining both the soluble and insoluble fatty acids by the Reichert-Meissl 

 number. 



The chemical estimation of starch, E. Giantukco {BoL Chim. Pharm., S9 

 {1900), pp. S29-3S5; Srliiniz. \V>'Itiis<-}ir. Fharm., 38 {1900), p. 348; abs. in Ztschr. 

 Uniersurh. Nahr. u. Genussintl., 4 {1901), No. 1, pp. 40-41)- — This method is based 

 on the tendency of carbohydrate bodies to unite with earthy bases, and is carried 

 out in a manner somewhat similar to the method of Asboth, excejit an aluminum 

 salt is used instead of barium hydroxid. 



A solution of potash alum is made up, in which 1 cc. contains 0.060769 gm. alum, 

 equal to 0.01 gm. aluminum hydroxid. Of this solution 10 cc. is used for each 0.5 

 to 1.5 gm. starch. With commercial starch 2.5 gm. of finely powdered, well mixed 

 substance is put into a Ijeaker, and 150 to 200 cc. water and 15 cc. of the alum solu- 

 tion added and thoroughly mixed. A small excess of ammonia is then added and 

 the precipitate l)rought upon a filter, washed until no sulphate reaction is given, 

 dried at 100°, and weighed. With meal, 3 gra. of the substance is made into a 

 dough with a little water, and then the starch washed out into a beaker with a fine 

 stream, and the process continued as indicated above. 



Estimation of dextrose and dextrin in commercial g-lucose, L. Lindet {Ann. 

 Chim. Analyt., 6 {1901), No. 2, pp. 43-45). — In the method proposed the total carbon 

 is estimated by combustion with cupric oxid in the usual manner, and the rotary 

 power of the glucose determined. From the carbon obtained by combustion the 

 combined weight of the sugars present is calculated as CgHi-jOg. From this figure and 

 the rotary power of tlie glucose, the relative pro])ortion of dextrose and dextrin is 

 calculated. In making the estimation the specific rotary power of dextrose is i)laced' 

 at 52.5°, of dextrhi at 195°. 



Influence of the nature and intensity of light on the inversion of sucrose 

 by mineral acids, H. Gillot [BuL Acad. Roy. Sd. Belg., 1900, pp. 863-874; nbs. in 

 Jour. Chan. Sor. [Loiidon'], 80 {1901), No. 460, I, p. 127). — Light of all wave lengths 

 promotes inversion of sucrose in the presence of sulphuric and hydrochloric acid. 

 The rays in the blue, violet, and ultra violet are much more active than those in the 

 yellow or red. 



The determination of tragacanthin and dextrin in cacao and chocolate and 

 the estimation of the dextrins by polarization, P. Wei.mans {Ztschr. Ocffcut. 

 Chem., 5 {1900), j)j>. ^';,SW.V.>'; <ths. in Chein. CentbL, 1901, I, No. 1, pp. 65, 66). 



Method of dissolving cellulose, Thiele {Rer. Prod. Chim., 3, p. 325; abs. in 

 Jour. Soc. Chem. Ind., 20 {1901), No. 2, p. 119). — Cotton wool mercerized in caustic 

 soda, dried, and immersed in an ammoniacal solution of cupric oxid will dissolve 

 almost immediately at ordinary temperature. 



Elementary organic analysis, F. G. Benedict {Easton, Pa.: Chemical Publishing 

 Co., 1900, pp. VI-\-86, figs. 15). — Description of apparatus and methods employed in 

 makuig detenninations of carbon and hydrogen in various combinations. 



