44 MILK AND ITS HYGIENIC RELATIONS 



ments give a low amount of milk, the quantity rising again when 

 the physiological requirements are fulfilled. Above this, however, 

 although high feeding may produce an increase both in the amount 

 of milk and in the butter- fat, this rise is in no way proportional 

 to the increased amount of food. This has been considered in 

 greater detail on pp. 20, 21. 



The presence of lecithin in milk has been investigated by several 

 authors, with positive results. Stocklasa says that i litre of cows' 

 milk contains from 0-90 to 1*13 gramme of lecithin, and the same 

 amount of human milk contains from 170 to r86 gramme. 1 



There is no evidence as to the nutritional value of lecithin in milk. 



Sugar. The figures already quoted for the sugar content of 

 cows' milk and human milk hardly require amplifying. 



In spite of the use of different methods of estimation of the 

 sugar, fairly concordant results have been obtained. 



There seems no doubt that the sugar content of cows' milk 

 is much below thaf of human milk. Lust, using the colorimetric 

 method, has confirmed the figures for human milk ; and Antenrieth 

 and Funk, using the same method, found the average amount 

 to be 7-1 per cent. 



The sugar content appears to be hardly affected by the period 

 of lactation or by the composition of the dietary, so long as the 

 dietary is sufficient for the needs of the organism. 



The experiments of Cathcart and Paton, already quoted, show 

 that when the body is artificially depleted of glucose, the milk supply 

 falls, and also the sugar content. 



Lust endeavoured to raise the lactose content of the milk by 

 feeding nursing women with large amounts of dextrose and other 

 sugars. In a few cases a very slight rise was noted, which might 

 perhaps be attributed to the additional amount taken. No distinct 

 alteration in the content of lactose was, however, obtained. 



This absence of effect due to increasing the amount in the 

 food is in harmony with the work on other constituents considered 

 later under the several headings. 



It appears from the work of Porcher, Cathcart and Paton, and 

 others, that the sugar in the milk is synthesised in the gland itself 

 from the carbohydrate present in the blood. This subject is, 

 however, beyond the scope of the present work. 



REFERENCES IN CHAPTER III 

 The Organic Constituents of Milk 



ANDERSON. See Rosenau and Anderson. 



AUTENRIETH AND FUNK, ' Ueber cine kolorimetrische Bestimmungdes Milch- 



zuckers im Harn und in der Milch,' Munch, med. Wochensch. 1911, 



lix. 1717. 



1 Cp. also Schmidt-Miilheim and Bordas and Racgkowsky. 



