EXERIMENT STATION RECORD. 



Vol. 40. 'Abstract Number. No. G. 



RECENT WORK IN AGRICULTURAL SCIENCE. 



AGRICULTURAL CHEMISTRY— AGROTECHNY. 



The physiochemical state of the proteins in cow's milk, L. S. P AIMER ami 

 R. G. Scott (Jour. Biol Chem., 37 {1919), No. 2, pp. 87i-28i).— Experiments 

 are reported In which fresh skim milk, skim milk preserved with 5 per cent 

 chloroform, skim milk preserved with o.o.i per cent formaldehyde, and the 

 lactic acid whey from fresh skim milk were filtered through Pasteur-Ghamber- 

 land filtering tubes under pressure. The total protein passing through the 

 tillers was determined by precipitation with Almen's tannic acid reagent, and 

 the nonprotein nitrogen in the filtrate from the precipitate thus formed. 



The amount of noncasein protein recovered In the filtrate did not in any case 

 exceed 10 per cent of the noncasein protein in the original milk, and in most 

 cases was considerably less than this figure. There was also only a partial 

 recovery of the nonprotein nitrogen of the original milk in the experiments 

 witli chloroformed and formaldehyde-treated milk. From these results, which 

 are not in agreement with those obtained by Van Slyke and Bosworth (E. S. K., 

 82, ]). c>n7), the authors conclude that the variation in the size of the pores of 

 different I'asteur-t'hamberland filters shows the fallacy of drawing conclusions 

 regarding the true state of solution of noncasein proteins of milk based on 

 filtration studies of this character. 



Data are also presented which show that chloroform left in contact with 

 milk greatly depresses the amount of protein which can be recovered from 

 casein filtrates by this method, probably by a partial precipitation of heat- 

 coagulable protein. This is thought to explain the fact that chloroformed 

 milk apparently allows less heat-coagulable protein to pass through the 

 Pasteur-Chamberland filter than sour milk or milk preserved by formaldehyde. 



The state of proteins in cow's milk, L. L. Van Si.ykk and A. \V. BOSWOBTB 

 {Jour. Biol. Chun., 37 (1919), .\<>. 2, pp. 2s.',. .'><■'). —In reply to the preceding 

 paper, attention is called to the fact that the finer filters employed by Palmer 

 and Scott would require passage through them of a greater volume of liquid 

 for saturation, and that the first 100 cc. or so of the fill rate should conse- 

 quently have been discarded before drawing samples for analysis. 



It is also pointed out that the action of chloroform on milk is a progressive 

 one, and that, therefore, the changes noted in the preceding work at the end of 

 seven days are not comparable to those which might have taken place in 

 filtrations lasting from 12 to 'M hours. 



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