130 '^he Philippine Journal of Science i9i6 



principally in the liquid oil from which the fats with higher 

 melting point have been separated. This role of fats in promot- 

 ing growth has been confirmed by McCollum and Davis. ^^ Funk 

 and Macallum '" consider that their experiments show the "in- 

 ability of either butter or butter fat to stimulate the growth 

 of young rats;" yeast contains a growth-promoting principle, 

 presumably a vitamine. McCollum and Da\ds " conclude that 

 there is an accessory water-soluble, growth-promoting substance 

 in milk whey, wheat embryo, and egg yolk. 



The growth-promoting substances are apparently not in- 

 fluenced by heating. Osborne and Mendel ^® find that heating 

 butter fat for two and one-half hours was without destructive 

 effect. McCollum and Davis ^^ state that milk whey can be kept 

 at a boiling temperature for six hours without appreciable loss 

 of activity of the accessory water-soluble, growth-promoting sub- 

 stance in milk whey; they also furnish evidence that this sub- 

 stance (present in lactose preparations) is not destroyed by 

 autoclaving. They ascribe the loss of the growth-accelerating 

 property of heated milk to changes in the casein which render it 

 nutritively inadequate." 



Our own experiments with dogs and particularly with pigs 

 have indicated that autoclaving the milk for two hours at 125°C. 

 has not affected appreciably either the growth-promoting prin- 

 ciples of the milk or the nutritive value of the caseinogen. Rec- 

 ords for forty-seven days of the experiment with dogs showed 

 that it required 12.4 and 12.1 cubic centimeters of milk for each 

 increase of 1 gram of body weight for the two puppies fed on 

 fresh milk; for the three given autoclaved milk the figures are 

 13.1, 13,5, and 12.8 cubic centimeters. For an increase of 1 

 gram in body weight of the pigs killed on the thirty-fourth day, 

 there were required 9.1 and 9.2 cubic centimeters of fresh and 

 autoclaved milk, respectively; similarly for the pair of pigs 

 killed the sixtieth day, 10.7 and 10.5 cubic centimeters, respect- 

 ively; and for the remaining pair of pigs, 11.2 and 10.0 cubic 



"Ibid. (1914), 19, 214. 



'"Ibid. (1915), 23, 413; see also MacArthur and Luckert, ibid., 20, 161, 

 and Bosworth, Bowditch, and Ragle, Am. Journ. Dis. Child. (1915), 9, 81. 



" Journ. Biol. Chem. (1916), 23, 181, 247. 



" Loc. cit. 



="Loc. cit. 



"Daniels and Stuessy, Am. Journ. Dis. Child. (1916), 11, 45, have 

 reported very recently that rats fed on boiled milk grow to about half their 

 normal size. Lane-Clapon, Journ. Hyg. (1909), 9, 233, has rather con- 

 clusively shown that there is no diminution of the nutritive value of milk 

 heated to boiling or dried (120°C.) when fed to young rats. 



