630 MILK. 



bination. This does not agree with the results of SIKES who found on 

 an average of only 42 per cent of the total P2O 5 in organic combina- 

 tion. Because of the large amount of casein (and calcium phosphate) 

 cow's milk is much richer in phosphorus than human milk. The relation 

 1*205 : N, according to SCHLOSSMANN/ is equal to 1:5.4 in human milk 

 and 1:2.7 in cow's mi-Ik. Woman's milk is poorer in mineral bodies, 

 especially lime, and it contains only one-sixth of the quantity of lime as 

 compared with cow's milk. The mineral constituents of human milk are 

 better assimilated by the organism of the nursing child than those of 

 cow's milk. Human milk is also claimed to be poorer in citric acid 

 (SCHEIBE 2 ), although this is not an essential difference. 



Another difference between woman's milk and other varieties of milk is 

 UMIKOFF'S reaction, which seems to depend upon the quantitative composition, 

 especially the relation between the milk-sugar, citric acid, lime, and iron (SIEBER 3 ). 

 This reaction consists in treating 5 cc. of woman's milk with 2.5 cc. ammonia 

 (10 per cent) and heating to 60 C. for 15-20 minutes, when the mixture becomes 

 violet-red. Cow's milk gives a yellowish-brown color when thus treated. 



According to RUBNER woman's milk contains about 3 p. m. soaps, but this 

 could not be substantiated by CAMERER and SOLDNER. They conclude that 

 woman's milk contains no soaps, or at least only very small amounts. They also 

 found the quantity of urea nitrogen in woman's milk to be 0.11-0.12 p. m., 

 although SCHONDORFF 4 found nearly twice this amount, namely, 0.23 p. m. 



In regard to the quantity of mineral bodies in woman's milk we have 

 the analyses of several investigators, especially of BUNGE (analyses A and 

 B) and of SOLDNER and CAMERER (analysis C). 5 BUNGE analyzed the 

 milk of a woman, fourteen days after delivery, whose diet contained very 

 little common salt for four days previous to the analysis (^4), and again 

 three days later after a daily addition of 30 grams of NaCl to the food 

 (B). The figures are in 1000 parts of the milk: 



K 2 O... . 0.780 0.703 0.884 



Na 2 0.232 0.257 0.357 



CaO.. . 0.328 0.343 0.378 



MgO 0.064 0.065 0.053 



Fe 2 O 3 0.004 0.006 0.002 



P 2 O 5 0.473 0.469 0.310 



Cl 0.438 0.445 0.591 



The relation of the two bodies potassium and sodium to each other 

 may, BUNGE believes, vary considerably (1.3-4.4 equivalents of potash 



1 Burow, Zeitschr. f. physiol. Chem., 30; Koch, ibid., 47; Wittmaack, ibid., 22; 

 Siegfried, ibid., 22; Nerking and Haensel, Bioch. Zeitschr., 13; Valenti, Biochem. 

 Centralbl., 4; Schlossmann, Arch. f. Kinderheilkunde, 40; Sikes, Journ. of Physiol., 34. 



2 Maly's Jahresber., 21. 



3 Zeitschr. f. physiol. Chem., 30. 



4 Rubner, Zeitschr. f. Biologic, 36; Camerer and Soldner, ibid., 39; Schondorff, 

 Pfliiger's Arch., 81. 



5 Bunge, Zeitschr. f. Biologic, 10; Camerer and Soldner, ibid., 39 and 44. 



