AGRICULTURAL CHEMISTRY AGROTECHNY. 507 



because many divergent figures for the normal moisture content are given in 

 the literature. 



The wheat flours studied came from various sources. The figures obtained 

 in these experiments varied between 12.75 and 15.09 per cent, with one excep- 

 tion, a flour prepared in the laboratoi-y, which showed only 10.83 per cent. 

 The moisture content of barley, rye, oat, rice, and bean flour varied between 

 10 and 12.8 per cent. In this work a modified Hoffmann method and ordinary 

 petroleum were employed. Toluene when used in the method forms an emul- 

 sion. 



In order to determine the fixation of water" by flour a method was devised 

 which consisted of shaking with water a known weight of flour in a tube 

 graduated in ^ cc, then centrifuging and reading the volume of the sedi- 

 ment. A similar test was made with the same quantity of flour in another 

 tube, but using 05 per cent alcohol instead of water, the difference between 

 the 2 figures constituting what the author terms the water-alcohol difference. 

 This test serves to differentiate many kinds of flour, as the water-alcohol fig- 

 ures for wheat and bean flour are negative and all others (rye, rice, potato, 

 oat, etc.) positive. The higher the negative figure for wheat flour, the better 

 the product. 



Nitrogen was determined by the Kjeldahl method as described in the Swiss 

 Food Manual ; gluten by Konig's method. The gluten percentage varied be- 

 tween 6 and 11 per cent when calculated to dry substance. Cellulose was de- 

 termined by a method which has been employed by the author for cacao prod- 

 ucts (E. S. R., 28, p. 711). Gliadin was determined according to Abderhalden's 

 method (E. S. R., 23, p. 410) but the results obtained were not accurate. 



The determination of water in plant substances with F. Hoffman's mois- 

 ture-determining apparatus, St. von Haydin (Ztschr. Untcrsuch. Nahr. u. 

 Genussmtl., 25 {1913), No. 3, pp. 158-160, fig. i).— The apparatus, which has 

 proved practical for soils, brewers' grains, malt, hops, barley, flour, potato 

 chips and flakes, starch, and yeast, consists of a copper distilling flask with a 

 thermometer and funnel. Into it is placed 20 gm. of the finely ground sub- 

 stance, 200 cc. of liquid paraffin, and 10 cc. of turpentine. The temperature is 

 raised in 8 minutes to 180° C, and then 10 cc. more of turpentine is added 

 and the temperature raised to 200° for 5 minutes. The water and turpentine 

 pass through a condenser into a graduated cylinder. The number of cubic 

 centimeters in the water layer multiplied by 5 gives the percentage of moisture. 



The sample is placed in a copper wire cylinder or holder 5 cm. in diameter, 

 which is lowered into the paraffin. It keeps the substance from sticking to the 

 distilling vessel and does away with filtering after each determination. The 

 determination can be made in 20 minutes w'hen using the holder. 



This method with cabbage checked to within an average of 0.3 per cent with 

 the water oven method, which takes 4 hours to obtain constant weight. 



Investigations in regard to varieties of egg yolk, with a contribution in 

 reference to the relation of the various kinds of yolk to one another, E. 

 Emmerich (Ztschr. Immunitatsf. n. Expf. Ther.. /, Orig., 17 (1913), No. 3, 

 pp. 299-30Jf). — It has been previously shown by Uhlenhuth and Ottolenghi that 

 egg yolk could be detected with the precipitation method in margarin, noodles, 

 etc. Schutze (E. S. R., 16, p. 845) also worked on this problem. After de- 

 scribing the technique used in preparing the precipitating serum, the author 

 reports tests made with noodles (prepared in the laboratory and purchased in 

 the open market), macaroni, etc. The results show that a highly specific 

 antiserum can be prepared which will detect egg yolk in baked goods, but that 

 with noodles, macaroni, and similar goods the results are often difficult to ob- 



38196°— No. 6—14 2 



