348 EXPERIMENT STATION RECORD. 



jiiict's Id'iiij,' (IctcriiiiiK'd. TlKMiii'tli<"ls iiii'lu(lc<l dry cxtnu-tion, uteain Haturatioii, 

 ami saturation witli cold wator. In exporiincntH in clarifvin',' juices tests were made 

 (if the gelatinous hydrates obtained from the rare mineral monazite. The results 

 wore considered no better than those o])tained by hydrated alumina, which is noted 

 as having,' lon<: been discarded as a clarifying agent in sugar manufacture. The 

 electrical metiiod of clarilication was also tested. 



Dry defecation in optical sug-ar analysis, W. J). IJokne {Jour. Avur. Clinu. 

 Soc, i.'G {1904), No. 2, 2»p. 186-1V2). — In order to avoid the error due to the volume 

 of the precipitate formed in clarifying sugar solutions with subacetate of lead, the 

 author dissolves the normal weight of sugar in exactly 100 cc. of water and adds 

 powdered anhydrous lead subacetate. Comparative tests of this method with the 

 ordinary method are reported. "The dry defecation method has been employed 

 for several months in 2 sugar refineries with perfectly satisfactory results and with 

 the a<lded advantages of greater si)eed of work, the elimination of volume measure- 

 ments, and tlu- simplification of calculations." 



The hydrolysis of maltose and of dextrin by dilute acids and the deter- 

 mination of starch, AV. A. No yes et al. {Jour. Amer. Chem. Soc, 26 {l'J04), No. S, 

 •pp. '2(JC>-2S0). — Studies were made of the rate of hydrolysis of maltose and dextrin 

 under the conditions which obtain in the determination of starch by the method in 

 common use. Several series of experiments are reported. After following the laAv 

 of normal mass reaction approximately for a short time, the rate of hydrolysis became 

 much retarded. The hydrolysis was apparently more nearly complete in a 2 or 4 

 percent solution of hydrochloric acid than in a 0.5 per cent solution. A temperature 

 of 111° C. was believed to possess a slight advantage over a temperature of 100°. 

 The rate of hydrolysis for dextrin was about one-half of that for maltose. The 

 reducing power of the products obtainet\ by the action of extract of malt upon stare 1 1 

 indicated a composition of 74 to 78 per cent of maltose and 22 to 26 per cent < f 

 dextrin. 



" For the determination of starch we would recommend that, after filtration, 10 

 per cent by volume of hydrochloric acid (sp. gr. 1.125) should be added to the solu- 

 tion resulting froni the action of extract of malt on the material under examination. 

 After heating for 1 hour in a flask immersed in a boiling-water bath, making allow- 

 ance for the time required for the solution to attain the temperature of the liath, the 

 solution is cooled, enough sodium hydroxid is added to neutralize 90 per cent of the 

 hydrochloric acid used, the solution made uj) to a definite volume, filtered on a dry 

 filter if necessary, and the reducing jiower determined by Fehling's solution. One 

 hundred parts of glucose found in this manner represent 93 parts of starch in the 

 original material. The chemist should determine for himself, with pure glucose, the 

 ratio between glucose and copper oxid or copper for the solutions and method which 

 he uses." 



Concerning the hydrolysis of cellulose with sulphurous acid, F. Zimmer 

 {M\n. Landir. Inst. K. Univ. Breslau, 2 {1902), No. 1, pp. 245-247) .—In view of the 

 fact that alcohol is manufactured from sugar obtained from sawdust by treatment 

 with sulphurous a(!id, the author studied the chemical action involved and found 

 that the amount of sugar formed was directly dejiendent upon the concentration of 

 the acid, the limit of sugar formation being 15 per cent. In making the calculations 

 sugar was estimated as dextrose, but it was found to contain S.56 per cent pentosan. 



Investigation of the bodies called fiber and carbohydrates in feeding 

 stuffs, with a tentative determination of the components of each, P. 

 ScrnvEiTZER {Jour. Amer. Chem. Soc, 26 {1904), No. 3, pp. 252-262).— The crude fiber 

 and nitrogen-free extract in a number of samples of feeding stuffs were determined 

 by oflicial methods, and the individual cai-bohydrates making up the total carlw- 

 hydrate group were also determined by special methods which are very briefly 



