648 EXPERIMENT STATION RECORD. 



"As this study was untlcrtakcii chieliy to answer the question whether certain fats 

 used as I'ood by man couM be (hstinguished one from the other, I would say that 

 butter, oleo oil, neutral lard, cotton-seed oil, beef stearin, lard oil, and any of their 

 mixtures, whether called butterine or by any other name, can be distinguished one 

 fnjin tlie other with perfect certainty, and that in mixtures, even those containing a 

 certain i)r(>portion of l)utter, the nature (if the components can be ascertained with a 

 reasoiial>le degree of accuracy." 



The iodin number of cotton-seed, oil, peanut oil, and some other oils and 

 fats, J. J. A. Wi.JS {ZfHchr. Untersuch. Nalir. u. GenussitdL, G {1908), No. 16, pp. 692- 

 697). — Determinations made by the author's method of the iodin absorption of a 

 nnmlier of sam])les of oils and fats are reported. 



Readings on the Zeiss butyro-refractometer of edible oils and fats, H. C. 

 Lythgoe [Tech. Quart., 16 {1903), No. 3, pp. 222-226).— The author reports actual 

 readings of cocoanut oil, beef stearin, cacao butter, beef tallow, mutton tallow, lard 

 stearin, beef oleo, lard oil, peanut oil, rape-seed oil, yellow and black mustard oils, 

 sunflower oil, and poppy-seed oil, most of the samples being of known purity. A 

 table is given, in which the calculated readings of these oils and fats at different 

 temperatures are incorporated with the butter readings of Zeiss, the lard readings of 

 Hefelmann, and the olive oil and cotton-seed oil readings of Leach. The iodin num- 

 ber and specific gravity of beef stearin, lard stearin, beef oleo, and lard oil are also 

 reported. 



Acido-butyrometric analyses of whey, P. Wieske {Bev. Gen. Lait, 3 {1903), 

 No. 2, pj>. 30-34, fig. 1). — The Adams, Gottlieb, and Gerber methods of determining 

 fat were compared on 16 samples of whey. Duplicate determinations by the (jerber 

 method showed no greater variations than by the gravimetric methods. The results 

 of the 3 methods agreed closely. 



The determination of fat in skim milk, C. Barthel {Rev. Gen. Lait, 3 

 {1903), No. 2, pp. 25-29). — The Adams and Gottlieb methods were compared on 

 whole and skim milk. The Adams method gave too low results in the case of skim 

 milk obtaineil from milk subjected to considerable agitation liefore separation, Avhile 

 the Gottlieb method was believed to give reliable results under all c-ircumstances. 



Determination of fat in milk by the Adams, Gottlieb, and Gerber methods, 

 M. SiEGFELD [Ztschr. UittersucJi. Nahr. u. GenussmtL, 6 {1903), No. 6, pp. 259-271). — 

 A large number of duplicate determinations by each of these methods, extending 

 over a number of years, are reported. No more accurate results are believed to be 

 obtained by one of the methods than by another. The possible sources of error in 

 each method are pointed out. 



Investigations on the Gottlieb-Rose method of fat determination, M. Popp 

 {Ztschr. Untersuch. Nahr. n. GenussmtL, 7 {1904), -Vo. 1, pp. 6-12). — According to the 

 author's experience the Gottlieb- Rose method is simpler, shorter, and more accurate 

 than other gravimetric methods of determining fat in milk. In one series of experi- 

 ments a study was made of the effect of allowing the sample to stand for varying 

 periods, from i to 6 hours, after the addition of the ammonia, alcohol, ether, and 

 petroleum ether. About 1 hour is recommended. 



In another series of experiments comparison was made of ammonia of different 

 concentrations (sp. gr. 0.98 to 0.91, corresponding to NH3 4.8 to 24.99 per cent). 

 The result showed no greater variations than with the use of the concentration (sp. 

 gr. 0.96) recommended by Gottlieb. Practically the same figures were obtained by 

 the weakest ammonia and double the usual amount of the strongest ammonia used. 



Qualitative reactions of hydrogen peroxid and their use in the examina- 

 tion of milk, C. Arnold and C. Mentsel {Ztschr. Untersuch. Nahr. u. GenussmtL, 6 

 {1903), No. 7, pp. 305-309). — The different tests for hydrogen peroxid are men- 

 tioned and their application to the detection of this substance in raw and heated 

 milk is briefly described. 



