114 EXPERIMENT STATION RECORD. 



Th.e acid content of coconut oil, L. Allen {Chem. Rev. Fett u. Harz Indus., 

 18 (1911), Wo. 5, pp. 112, 113; abs. in ZtSQhr. Angew. Chem., 2,1^ (1911), No. 29, 

 p. 1386). — As it has become a custom in commerce to calculate the percentage 

 of free-fatty acids as coconut oil fatty acids, the author points out the fact 

 that the middle molecular weight of these acids has not been definitely estab- 

 lished. On this account he recommends inserting the free-fatty acid figures in 

 the report as such and to let the coconut oil fatty acid figure follow it. 



A new method for determining' oil adulteration by mineral or resin oils, 

 A. E. OuTEKBRiDGE, Jr. (C/tew. Engin., 14 (1911), No. 2, pp. SIjl, 3.'f8; Cci. Amer. 

 Sup., 72 (1911), No. 1861, p. 155). — Mineral oils, so-called whether de-bioomed 

 or not, when present in vegetable oils can be detected by exposing them to the 

 rays of the ordinary inclosed arc light. In this light the fluorescence of the 

 mineral oil is highly intensified. Standards, according to the author, can be 

 prepared with mixtures of linseed oil and various amounts of mineral or resin 

 oils for making a quantitative determination of foreign oils in vegetable oils. 

 He also points out that soy-bean oil is an excellent substitute for linseed oil in 

 core making for the iron founding industry, and furthermore that it is better 

 than cotton-seed oil. 



The fluorescent test for mineral and rosin oils, P. H. Walker and E. W. 

 BouGHTON (U. S. Dept. Agr., Bur. Chem. Circ. 84, pp. 2). — ^The Outerbridge 

 method noted above was tested with pure linseed oil, other fatty oils of known 

 purity, turpentines, aftid various mixtures with mineral oils. 



It was found that many samples of vegetable oils of undoubted purity showed 

 marked fluorescence, in some cases as marked as that of many pure mineral 

 oils. '* It appears, therefore, that while it is interesting to know that the in- 

 closed arc is a very convenient means of strongly magnifying fluorescence, this 

 fluorescence is not proof of the presence of mineral or rosin oil." 



The uviol light was also tried as a source of illumination but found to be in 

 no way equal to the inclosed arc. 



Cotton wax, E. Knecht and J. Allan (Jour. Sac. Dyers and Colourists, 27 

 (1911), No. 6, pp. 142-146; al)s. in Jour. Sog. Chem. Indus., 30 (1911), No. 13, 

 p. 813). — Raw cotton when extracted first with light petroleum ether and then 

 with benzol yields 2 fractions of the wax, the first of which is dull yellow in 

 color, odorless, and resembles beeswax as regards texture and fracture. The 

 physical and chemical constants of the first fraction are described in detail. 



Report on method of determination of g'lycerol, E. Probeck (Jour. Indus, 

 and Engin. Chem., 3 (1911), No. 4, PP- 253, 25 Jf). — The acetin method, according 

 to this author, always yields results which are from 0.2 to 0.5 per cent low, 

 no matter how careful the procedure is carried out. This is not due to impuri- 

 ties present in the mixture but to errors introduced during the process of 

 manipulation. 



The author prefers the bichromate method when acrolein and other volatile 

 aldehydes are absent. When aldehydes are present these are removed before 

 adding the bichromate solution. The .use of a blank test simplifies the method 

 considerably, and yields more accurate results than a method which necessitates 

 the purification of the glycerin. 



Hippuric acid as th.e cause of the failure of the spectroscopic test for 

 hemoglobin in urine, F. A. McDeemott (Jour. Amer. Chem. Soc, 33 (1911), No. 

 6, pp. 992-995). — Hippuric acid was found to decompose hemoglobin and thus 

 prevent the appearance of the characteristic absorption band of this pigment 

 in the spectroscope. This can be prevented by previously neutralizing the 

 hippuric acid with ammonia. 



