BREAST-FEEDING 157 



various special foods or substances in the production of milk. 

 The available evidence is to the effect that no special influence upon 

 the secretion of milk is exercised by any one particular substance 

 directly. 



What is really essential is that there should be a sufficient 

 amount of food taken, which must contain a sufficiency of the 

 materials essential for the daily life of the maternal organism, 

 i.e. there must be enough protein, fat, carbohydrate, salts and 

 water. Schlossmann in 1900 quoted several cases which had come 

 into his practice where the wet-nurses had a plentiful supply of milk 

 while in the institution. Here the food was ample, reasonably 

 varied, perhaps rather coarse, but what each woman was accustomed 

 to in her own home. On being sent as wet-nurse to a private 

 house, a woman not infrequently lost her milk. Inquiry showed 

 that although sufficient food was provided, frequently of a highly 

 nutritious kind, it was not such as the woman liked. In conse- 

 quence she would not eat it, and the milk supply failed after a short 

 period. When she returned to the institution the milk supply 

 was restored. 



A considerable amount of work has been carried out upon the 

 relation of the amount of milk secreted by cows to special con- 

 stituents of the food. This has already been considered in 

 Chaps. II and IV, where it was shown that unless any particular 

 constituent of the food is decreased beyond the physiological limit 

 for the organism the amount of milk given by the gland is not 

 affected. When the amount of any essential constituent falls 

 below the physiological limit, the supply also falls. 



It would seem that the milk given by cows can be to some 

 extent increased by an additional amount of food, and that if 

 the food-supply is diminished below the physiological limit, the 

 amount of milk produced falls off. Conversely, if the amount of 

 food-stuff is increased, it is possible to increase the amount of 

 milk to some degree, although the increase is not proportional 

 to the amount of food given. 1 This subject is also dealt with 

 by Claus, who showed that a decrease in the food reduces the 

 amount of milk given, and he suggests that the expense of the addi- 

 tional food might be greater than the value of the corresponding 

 milk produced, and that it might pay farmers better to give less 

 food and obtain rather less milk. 



It is probable that many cases of failure of lactation in women 

 have been caused by the absence of proper nourishment for the 

 mother. The experience which has been gained at institutions, 

 where dinners for nursing mothers are provided, is to the same 

 effect. The published figures available from these dining centres 

 are somewhat fragmentary and for the most part too few in number 

 for considerable stress to be laid upon the experience obtained 



1 Cp. table on p. 21. 



