46 INORGANIC FOODSTUFFS 



normally receive iron in our diet, for we only partake of inorganic 

 salts of iron as a therapeutic measure, there can be no question but that 

 we can absorb, assimilate and utilize the iron contained in organic, 

 non-ionized compounds. 



It will be recollected that the iron in hemoglobin or hematin does 

 not yield the ammonium-sulphide test for iron. On administering 

 hematin or hemoglobin to mice which have undergone iron-starvation, 

 however, and applying the iron-sulphide test to various parts of the 

 intestine, we ascertain the remarkable fact that the duodenum and the 

 cecum yield the iron-test just as they do when inorganic iron is admin- 

 istered. In other words, the iron in the process of digestion in the 

 duodenum has become loosened from its combination in the hematin 

 radical and set free as an inorganic or at least an ionized salt of iron. 

 Since the iron, immediately subsequent to absorption, appears in the 

 same condition whether administered in the ionic form or not, there 

 would appear to be no very good reason for supposing that inorganic 

 salts of iron are not utilized to nearly as great an extent as the organic 

 salts of iron. The most specific disadvantage which attends the use 

 of inorganic salts of iron is their irritating or corrosive action upon the 

 intestinal epithelium, a corrosive action which, like that of mercury 

 salts, is probably to be attributed to the formation of insoluble protein 

 salts of the metal within the epithelial cells. This leads to the dis- 

 ruption of the gelatinous structures of the cells and their conversion 

 into granules or flocculi which, no longer being held together by the 

 cohesiveness of a jelly, fall apart with consequent disintegration of the 

 cells. Many individuals who display an " idiosyncrasy" or exceptional 

 sensitiveness to intestinal irritation are very severely affected by this 

 corrosive action of iron-salts and for this reason the general employment 

 of non-ionized organic compounds of iron in therapeutics, such as 

 hemoglobin or hematogen, is much to be preferred. 



With the exception of the disadvantages arising from the corrosive 

 action of inorganic salts of iron, therefore, the ionized and unionized 

 compounds would appear, so far as the above-cited evidence goes, to 

 be equally useful sources of iron in the diet. There are certain impor- 

 tant facts, however, which would appear at first sight to bear out the 

 contention that inorganic salts of iron, notwithstanding their absorp- 

 tion, are not utilizable for the synthesis of hemoglobin. We have 

 seen that milk contains a very low percentage of iron in comparison 

 with other foods, especially in comparison with green vegetables, 

 certain fruits such as apples, and flesh. If sucklings are kept beyond 

 the normal period of lactation exclusively upon a milk diet, they become 

 anemic from lack of iron. If we compare rabbits which have been 

 allowed to change to a diet of green vegetables after the normal period 

 of lactation, with those which have been brought up upon an exclusive 

 milk-diet, we find that the former contain much more hemoglobin than 

 the latter. But the remarkable fact is that if we add inorganic salts 

 of iron to the milk-diet the total hemoglobin in the animals is not 



