508 EXPERIMENT STATION RECORD. 



Catalase in butter, Hesse {Molk. Ztg. [Hildesheim'i, 26 (1912), No. 6, pp. 

 81-S4). — This is a study of butters sent to the laboratory for examination and 

 judgment in regard to quality. The tests made were for water content, degree 

 of acidity, and catalase figure. 



For the catalase figure Henkel's apparatus (B. S. R., 22, p. 710) was used. 

 The procedure was as follows : One hundred gm. of butter was melted at 45° 

 C. and mixed with 40 cc. of water of the same temperature. After allowing the 

 mixture to stand for a time, 15 cc. of the watery fluid (buttermilk fluid) was 

 examined for catalytic activity. Certain errors in the method are pointed out, 

 but the results obtained, which are low, may be so calculated as to correspond 

 with buttermilk or normal milk. 



Some tests with mixtures of foreign fats with butter are included. 



The fatty acids of butter, Ida Smedley (Biochcm. Jour., 6 (1912), No. .}, 

 pp. 451-461, figs. 2). — It is pointed out that, in spite of the large number of 

 analyses of butter reported, considerable uncertainty still remains as to the 

 constitution of the fatty acids contained in butter. For instance, no work on 

 the constitution of hexoic (caproic) acid seems to have been carried out since 

 1823 ; therefore, among other things it seemed desirable to settle quite defi- 

 nitely the structure of hexoic acid present in butter. 



The work is summarized as follows : " No evidence of the presence of acetic 

 acid was found in the butter examined. The hexoic (caproic) acid present in 

 butter possesses the normal structure ; no indication of the presence of the 

 isohexoic acid was obtained. It seems probable that of all the naturally exist- 

 ing specimens of caproic acid which have been described, only that occurring 

 in the bacterial decomposition of proteins has a branched structure. The 

 proportion of stearic acid was estimated as from 10 to 15 per cent. Evidence 

 was obtained of the existence of lower members of the oleic acid series; the 

 iodin value of the decoic ester fraction is appreciably greater than those of 

 the fractions immediately preceding or following it. This may be regarded as 

 indicating the presence of a lower unsaturated acid, possibly of a decylenic acid. 



" The sodium-nitroprussid reaction, characteristic of aceto-acetic acid and 

 of acetone, was given by the butyric ester fraction obtained from 2 out of 5 

 samples of butter, esterified by sodium methylate at ordinary temperature ; the 

 remaining 3 samples gave negative results. The reaction may possibly have 

 owed its origin to the products of bacterial action ; it was observed in 2 cases 

 where Haller's acid method of esterification had been used." 



A new method for the determination of total nitrogen in urine, O. Folin 

 and J. C. Farmer (Jour. Biol. Chem., 11 (1912), No. 5, pp. 493-501. figs. 2; 

 abs. in Zentbl. Expt. Med., 2 (1912), No. I4, pp. 637, 638).— As a substitute for 

 the Kjeldahl method for determining the total nitrogen in urine, a micro-chem- 

 ical method is proposed which is based on the Kjeldahl decomposition process 

 and the Nessler and Folin method of determining ammonia, is as follows: 



Five cc. of the urine is measured with an Ostwald pipette into a 50-cc. meas- 

 uring flask ; where the specific gravity is lower than 1.018, only 25 cc. solu- 

 tion of urine is used. The bottles are then filled to the mark with distilled 

 water, and 1 cc. of the diluted urine is brought into a large test tube, to which 

 are added 1 cc. of concentrated sulphuric acid, 1 gm. of potassium sulphate, 1 

 drop of a 5 per cent copper sulphate solution, and a sliver of glass. The solu- 

 tion is then boiled for G minutes over a micro-burner, allowed to cool for about 

 3 minutes until the contents of the test tube begin to congeal, and then 6 cc. of 

 water and 3 cc. of a saturated sodium hydroxid solution are added. The am- 

 monia, which is liberated, is then removed with the aid of a suction pump 

 smd absorbed in a solution consisting of 20 cc. of water and 2 cc. of decinormal 



