THE INORGANIC CONSTITUENTS OF MILK 53 



in rather older children fed with egg-yolk and spinach. About 

 59 per cent, to 70 per cent, of the iron was absorbed, and 55 per 

 cent, to 70 per cent, retained. Ferratin was also tried, and it was 

 found that about 23 per cent, was retained. 



Langstein investigated the iron metabolism of two breast-fed 

 infants in the early weeks of life, one being twelve weeks and the 

 other eight weeks old. 



He found that the first child retained about 0-255 m g- per day, 

 and the second child 0*188 mg. per day. Hence there is no need 

 for a store of iron in the body to provide for growth. 



Further work by Langstein and Edelstein also showed a positive 

 iron balance in the early days of life. They obtained samples 

 of the mother's milk, and accurate information as to the amount 

 taken by the infant. A positive balance of 32 to 39 per cent, 

 of the total intake in the early days of life, and of about 41 per cent, 

 in the second week, was found. 



It seems evident that the milk of the species contains the 

 amount of iron necessary for growth. 



Some experiments have been carried out in order to ascertain 

 whether the iron content of milk can be raised by the addition of 

 iron to the food of cows. 



It appears that at one period, evidently before the year 1902, 

 a German firm advertised an article called ' Eisenzucker/ This 

 substance, when added to the food in sufficient quantities, was said 

 to increase greatly the iron content of the milk, and to render the 

 milk highly valuable for cases of anaemia, &c. The precise iron 

 content which could be obtained was stated to be 0-0842 per cent, 

 of ferrous oxide. 



Giordani (1902) states that the injection of this substance into 

 goats and rabbits caused an increase in the iron content of the 

 milk, which was more than doubled in some cases. He found 

 an accompanying slight reduction in the total milk output, but no 

 change in the other constituents. 



Mai (1910) undertook feeding experiments with ' Eisenzucker.' 

 The method used for the iron estimation is only claimed to be 

 relatively accurate, but Mai obtained no evidence of a rise in iron 

 content, unless a rise of o-oooi gm. per cent, on two occasions can 

 be counted as an increase due to feeding. The substance itself was 

 found to be the pharmacopceial preparation known as Ferrum 

 Oxy datum Saccharatum. Mai states that the dairy on whose behalf 

 the work was carried out informed the proprietor of the failure 

 of the preparation, and powder was then offered to the dairyman 

 with the suggestion that it should be added directly to the milk. 



Soxhlet also carried out feeding experiments on cows, using 

 large quantities of ' Eisenoel ' and of haemoglobin. A rise of o-i mg. 

 per litre occurred, which might be attributed to the feeding, but he 

 concludes that alterations in iron content of the milk cannot be 

 obtained by feeding with iron compounds. 



