618 EXPERIMENT STATION RECORD. (Vol. 87 



filtrate should be taken, treated with an excess of dry phosphotungstic acid, 

 made to volume, Altered, and the filtrate tested for complete precipitation. 



When the precipitation is complete sufficient dry potassium chlorid Is added 

 to precipitate the excess of phosphotungstic acid. The potassium phospho- 

 tungstate Is filtered off and the filtrate tested for the presence of creatinin. 

 When an appreciable excess of phosphotungstic acid has been used for clari- 

 fication not more than a trace of creatinin should be found. The sugar is then 

 determined in aliquot portions of 25 cc. of the filtrate by AUlhn's method and 

 the reduced copper by Low's iodid method. 



In view of the reported increased formation of dextrose in muscular tissue 

 during grinding for analysis, it is suggested that when the dextrose content 

 of the sample is to be determined immediately after the death of the animal 

 the weighed sample bo cut into several pieces, plunge<l into boiling water, and 

 the boiling continued for from five to ten minutes. The clear liquid should 

 then be decanted, the residue ground in a meat grinder, and the extraction 

 carried out as usual. 



Determination of sugar in hay and turnips, R. K. Kristenskn (Tidsskr. 

 Flantcavl. 23 (1916), Xo. 5, pp. 757-777 ).— Continuing previous work (E. S. R.. 

 36, p. 807), it has been found that eltiier water or alcohol can be satisfactorily 

 used for extraction of the sugar In the materials. For cruciferous plants alco- 

 hol extracts have been found to jield the most reliable results. Basic lead 

 acetate could not be used for clarifying the solutions, but mercuric nitrate was 

 entirely satisfactorj', and its use is recommended. The reduction of the pre- 

 cipitated cuprous oxid to metallic copper is considered not to be necessary 

 iinless the solution has not been clarified by some defecating agent. 



Determination of the alkalinity and phosphoric acid content of foodstuffs, 

 I. M. Koi.THOFF iChnn. MeckbL, llf (1917), Xo. 2f pp. 5^7-<>5S ) .— This is a 

 dLscu.ssion of the comparative merits of the author's method (E. S. R., 36, p. 

 204) and the method of Pfyl,* which depends on precipitating the phosphates 

 as tricalcium pho-^^phate with calcium chlorid and titrating the liberated hydro- 

 chloric acid with standard alkali, using plienolphthaleln as an indicator, after 

 converting the phosphates into primary phosphates. Some comparative ana- 

 lytical data obtained in the examination of pure solutions and the ash of bread, 

 pepper, and milk powder by the above methods and the procedure of Lorenz 

 (E. S. R., 13. p. 14) are submitted. 



It is concluded in general U)at the method of Pfyl docs not possess any ad- 

 vantages over the method previously proposed by the author. 



Specifications and directions for testing milk and cream for butter fat, 

 O. F. HuNziKKK (,Iour. Dairy Sci.. 1 (1917), No. 1, pp. ."JS-.}^).— This is a n«port 

 of the data on odicial methods of testing milk and cream for milk fat submitte*! 

 nt the Official Dairy Instructors' Association meeting held at Springfield, Mass., 

 October 16 and 17, 1916 (E. S. R., S5, p. 799). 



The Shrewsbury and Knapp process for the estimation of coconut oil, G. D. 

 Elsdon and C. R. Bagshawk (Analyst, 42 (1917), No. 49S, pp. 72-SS, figs. 2). — 

 The authors have studied the method previously noted (E. S. R.. 24, p. 515) 

 and have found tliat the most suitable strength of alcohol to u.se Is of specific 

 gravity 0.92 at 15.5° C. With alcohol of this strength concordant results could 

 be obtained with mixtures of coconut oil and butter and coconut oil and mar- 

 garin containing up to about 00 to 65 per cent coconut oil. With mixtures 

 containing greater percentages of coconut oil the results obtained were not so 

 satisfactory. Where the samples contained 70 per cent or more of coconut 

 oil, alcohol of specific gravity 0.91 was found to yield satisfactory results. 



«Arb. K. Qendhtsamt, 47 (1914), No. 1, pp. l-ll. 



