514 EXPERIMENT STATION EECORD. 



the basis of oxi)erionco, the antlior discusses the discoloration which may occur 

 in the manufacture of i)iclvies and other food jtroducts owinj: to tiie i»resence of 

 iron. In pnx-essin},' canned goods of different sorts hydroj^en sulphid causes 

 discoloration by actiufjc upon the iron present, for instance, in the water used 

 in iircparinj^ the can contents. 



Indirect determination of the total solids in milk, D. (Jiriijaldo and A. 

 Peluffo {Monit. Sci., >,. scr., i.f {l!)()<)). II, No. 812, pp. J,H!)-.',D9) .—ThiB is a 

 description of the orijrin and basis of the formulas emi)loyed to determine the 

 total solids of milk indirectly. 



Determination of fat in dairy and other products by Gottlieb's method, 

 L. (iuuNiiUT {Ztschr. Anali/t. Chvm., .'/.S (inO!)), Xo. 12, pp. 7.S7-7.s'.7, fi(/s. 2).— 

 A description of the various forms of ap])aratns and moditicatious of (Jottlieb's 

 method for th(> determination of fat. 



An anaeroxydase and a catalase in milk, Sarthou (Chcm. Ztff., 33 (1909), 

 No. JJfl, p. 12JfO, fig. 1). — It is stated that milk contains an anaeroxydase which 

 is soluble in water and milk serum and also a catalase which is insoluble. Fur- 

 ther, that insoluble casein oxidizes ?j-phenylendiamin but not guaicol, and that 

 the former is an extraordinarily sensitive reagent which must be taken into 

 consideration when testing for oxidizing ferments. 



About an anaeroxydase and a catalase in milk, F. Bordas and Touplain 

 {Cimpt. Roul. Acad. 8ci. [Prtr/.s-], J.'i9 (1909), No. 22, pp. JOll, 101^).— The 

 authors state that the presence of a catalase and anaeroxydase as noted by 

 Sarthou above is not proved, and that the color reaction produced in i-aw milk 

 is brought about by the decomposition of hydrogen peroxid and is due to the 

 calcium caseinate. 



Detection of cows' milk in asses' milk, L. Grimbert (Jour. Pharm. ct Chim., 

 6. ser., SO (1909), No. 7, pp. 29S-S00; ahs. in Vhnn. Zifi.. 33 (1909), No. IJfl, 

 Rcpert., p. 605). — As asses' milk contains no anaeroxydase the presence of cows' 

 milk, which contains anaeroxydase, can easily be detected with a 1 per cent 

 guaiac solution and peroxid of hydrogen. 



The catalase reaction of colostrum, J. Van Haarst (Mrded. Rijkfi Ifoogere 

 Land, Tuin en Bosclihomosch., 1 (1908), pp. 27-32). — On the basis of his in- 

 vestigations the author concludes that where the catalase content is higher 

 than the normal, abnormal milk is to be suspected. 



About the refraction and specific gravity of calcium chlorid milk serum, 

 G. WiEGNKR and G. Yakuwa (Milchw. ZrntM.. 5 (1909). Nos. 11. pp. Ji73-.',87 ; 12, 

 pp. 521-530). — The authors conclude from their work that the specific refrac- 

 tion of the calcium chlorid serum is independent of the temperature and, in 

 very wide limits, of the concentration. It is shown that water added to the 

 extent of only 50 per cent increases the specitie refraction from 0.205G to 0.2058. 

 Calculated from the chemical composition of the serum (refractive index at 

 17.5° C, specific gi*avity at 15° compared with water at 15°), the specific re- 

 fraction is 0.20552. 



The specific refraction is also independent of the milk, sugar, protein, and 

 citric acid of the serum, but is in a slight degree dependent upon the ash. If 

 the ash content falls by 0.3 per cent the specific refraction increases from 

 0.20.56 to 0.2058. The tests demonstrate its constancy with different fat. pro- 

 tein, and sugar contents of the milk. Watering the milk to the extent of 

 50 per cent in one experiment showed higher figures (within tho limit of the 

 calculated ones), but watering to the extent of 25 ]ier cent showed nothing. 



The work further indicates that the refractometric and the specific gi'avity 

 methods are of equal value and importance. As to their relative accuracy, 

 a variation of 1° of the immersion in the refractometric scale is equivalent to 

 o.(t(ii of specific gravity. 



