822 EXPERIMENT STATION RECORD. 



The determination of saccharin, F. Wirthle {Client. Zlr/., 2n {1901), No. 77, 

 p. 816). 



Note on the approximate estimation of formaldehyde in milk, J. F. Liver- 

 SEBGE {Analyst, 26 {1901), No. 303, pj). 151, 152).— h. color reaction obtained by the 

 adition of a reagent composed of 25 cc. of normal ferric chlorid in 100 cc. of pure 

 concentrated sulphuric acid. Ten cc. of the milk is placed in a 25 cc. stoppered 

 cylinder and the reagent added, 1 cc. at a time, from a burette and the color noted. 

 In the presence of formaldehyde a violet color appears which increases in intensity 

 with the amount of formaldehyde in the sample. 



Detection of formalin in milk, O. Henzold {Milch ZUj., 30 {1901), No. 40, 

 pp. 629, 630). — The addition of sulphuric acid to milk containing formalin gives a 

 distinct violet color at the contact of the two layers. 



The estimation of formaldehyde, Z. Peska {Chem. 7A(j., 25 {1901), No. 71, 

 p. 743). — A discussion of methods. 



Estimation of the acidity of the fat in foods, G. Loges and K. MtiiiLE 

 {Landw. Vers. Stat, 56 {1901), No. 1, pp. 95, 96). — The authors recommend the 

 direct extraction of the fat, carried out with 5 gm. of material and 100 cc. of water 

 and acid-free ether. An aliquot portion of the filtrate is taken for the determination 

 of the acidity, using an alcoholic potash solution containing 50 per cent of alcohol 

 for titrating. The results of a series of tests of this method with various foods are 

 shown in comparison with the ordinary method. The results are in every case 

 higher with the former method. 



The application of iodin monobromid in the analysis of fats and oils, 

 J. Hanus {Ztsehr. Untersuch. Nahr. u. Genussmtl, 4 {1901), No. 20, pp. 913-920).— The 

 author has made an extended study of the use of iodin monobromid in the analysis 

 of fats and oils. The formation of iodin monobromid, a gray, crystalline, metallic sub- 

 stance, soluble in alcohol and acetic acid, is given. A table is shown, giving the num- 

 ber obtained with this compound, in comparison with the TUiltl immber. The method 

 of obtaining the iodin monobromid numlii'r is as follows: 0.6 to 0.7 gm. of fat and 0.2 

 to 0.25 gm. of oil, or, in case the iodin nund)er is above 120, 0.1 to 0.15 gm. of oil is 

 put into a glass-stoppered flask of 200 cc. capacity and 10 cc. of chloroform added. 

 After the fat is dissolved 25 cc. of a solution made of 10 gm. of iodin monobromid in 

 500 cc. of acetic acid is run in, and after 15 minutes, with occasional shaking, 15 cc. 

 of potassium iodid solution ( 1 :10) added. The free iodin is then titrated with sodium 

 thiosulphate solution, using starch as an indicator. 



The advantage of the iodin monobromid solution in acetic acid over the usual method 

 of obtaining the iodin number is as follows: (1) The solution is more stable and 

 keeps for a longer time; (2) the results with the iodin mono1)romid solution are more 

 uniform and it is not necessary, therefore, to employ so many blank determinations; 

 (3) the fiask needs to stand only a quarter of an hour, so that a greater numl)er of 

 manipulations ma}' be (^arried out in a short time; and (4) the numbers obtained by 

 this method very closely approximate those obtained by i\u' usual method. 



A method for the quantitative separation of cholesterin from fat, E. KirTER 

 {Chem. Ztg., 25 {1901), No SI, p. 872). 



Concerning' lecithin compounds, H. J. Bin(; {Shmd. Arrh. Phi/sioL, 11 {1901), 

 Nos. 3~4, }>p. 166-175). — A chemical study of the compounds which lecithin forms 

 with sodium chlorid, sodium acetate, platinum chlorid, salacin, amygdalin, and a 

 number of other reagents, the purpose of the investigation t)eing to study the chem- 

 ical constitution of lecithin. 



Glycogen obtained by extraction Avith boiling water in comparison Avith 

 the total glycogen present, J. Nerkino {Arrh. Physiol. \_Pflnger'], 85 {1901), No. 

 7-8, pp. 313-319). — In the studies with the flesh of calves the author found that by 

 continued extraction with boiling water only about 5 or \ of the glycogen was 

 obtained. 



