716 EXPERIMENT STATION RECORD. 



" Heretofore it lias been customary to use a certiiin value for the si>ecific 

 lieat of milk or cream, without paying any attention to the temperature range 

 over which the material is to be heated or cooled. This is obviously wroog, 

 because the range plays a very important r'!trt from the standpoint of the 

 apparent specific heat value, and for that reason the above table was prepared, 

 although it is recognized that certain of the values may be in error because of 

 the assumptions that have been necessary. In addition to giving the values at 

 certain temperatures, the table gives the values over various ranges; these 

 were obtained by averaging the values for every 3° C. . . . Butter fat is com- 

 posed of a number of constituents which melt at different temiK>ratures, and 

 the abnormal values for specific heats include the latent heats of fusion of the 

 components of the fat." The highest si)ecific heat found over a wide temi)era- 

 ture range is in close agreement with the variations in the results that have 

 been obtained for the melting i)oint for butter fat by various investigators. 



" For many practical purposes the apparent specific heat is of as great value 

 as the true specific heat, jtrovided the value obtained for a particular tempera- 

 ture interval is obtained while applying the heat at such a rate that all of the 

 material meltable in tliat particular range becomes entirely melted and equi- 

 librium is established. . . . The values near the freezing ix)int of water are* 

 of importance in their bearing on the question of the relation of the specific 

 heats of ice cream mixes to the elTect on the palate. An ice cream very rich 

 in fat would not only have a low specific heat at low temi>erature, but, as is 

 apparent from the very great slopes of the specific heat curves and the high 

 maximum reached, it would adsorb heat rapidly with an increase in tempera- 

 ture. From the data obtained and disregarding other factors it appears that 

 an ice cream carrying considerable fat, when first coming in contact with the 

 warm palate and tongue, would give a sensation that was not disagreeably 

 cold. Then as the temperature increased because of the adsorption of heat by 

 the fusion of the fats the mass would be automatically maintained cold longer 

 than it otherwise would I'emain. In short, there is no sensation of extreme 

 coldness, but still the mass remains cold for a longer time than if smaller 

 amounts of fat were present. On the other hand, with low fat ice creams and 

 sherbets there is a sensation of extreme coldness when the material is first 

 taken into the mouth, but the mass soon warms np." 



The specific heat values for milk and milk derivatiA'es collected from the 

 dairy literature are tabulated. 



A rapid method for determining' crude fiber, IT. Kalxixg (Ztscltr. Gcsam. 

 Gctricdcw., 5 {1913), No. 1, pp. 6-8; «?>.s\ in Chem. Ztff.. 38 (191J,), No. 11, 

 Repert.. p. 48). — The method is a modification of Weender's. It consists of 

 diluting the mixture with water after each boiling, and, after settling, filtering 

 the supernatant fluid through gauze. The residue in the flask is placed in a 

 folded filter, and after the fluid has been filtered off it is retransferred to the 

 dish and finally placed in a tared folded filter and weighed after drying. See 

 also a previous note by Stiegler (E. S. R., 82, p. 314). 



Colorimetric test for uric acid in the urine, II. F. Host (Xorsk Mag. 

 TArgcvidemk. Med. Sclsk. Kristiania, 15 {1914). -Vo. 7, pp. 783-791. fig. 1; ab.<<. 

 in Jour. Amcr. Med. A.ssoc. 63 {1914). No. 8. p. 714). — A tabulation of the 

 author's "findings with simultaneous application of the various color tests in 

 vogue. They show that the Riegler method" is esiiecially simple and reliable 

 when the technique is slightly modified, as he describes, to render the reagent 

 more durable. It is a 1 per thousand solution of uric acid made by dissolving 

 0.1 gm. uric acid in a little distilled water in a 100-cc. graduated flask: adding 



" Ztschr. Analyt. Chcm., 51 (1912^. No. T-S. pp. 4G6-470. 



