308 ABSORPTION 



observed that very good results are obtained in the treatment of chlorosis by 

 administration of different preparations of inorganic iron, and observers were 

 pretty well convinced that these preparations were actually absorbed in the intes- 

 tine, Bunge set up the doctrine that all the iron which is added to the blood 

 and is the source of the iron contained in the haemoglobin, arises exclusively 

 from complicated proteidlike compounds, the hcematogens, which are formed in 

 the life processes of plants. Such compounds, resembling nucleo-albumins, occur 

 also in egg yolk, etc. That iron preparations are certainly of great use in 

 chlorosis, Bunge would not deny, but he explained the facts on the hypothesis 

 that inorganic iron compounds in some way protect the organic compounds from 

 decomposition in the intestine, and thus prevent the iron in them from being 

 split off. Other authors have advanced other hypotheses, and attempts have even 

 been made to explain the therapeutic effects of iron as the result of hypnotic 

 suggestion. 



However, it appears with greater definiteness from recent researches that 

 the so-called inorganic iron compounds are absorbed in the intestine (Kunkel, 

 MacCallum, Hall, Hochhaus, and Quincke et al.}. A research carried out a 

 short time ago by Abderhalden in Bunge's own laboratory shows the same thing, 

 namely, that iron furnished in inorganic compounds, in haemoglobin and haematin 

 is absorbed even in small doses, and without destroying the complicated iron 

 compounds. The absorption takes place through the activity of the epithelial 

 cells (cf. Fig. 119). These cells then deliver the absorbed iron either to the 

 leucocytes or directly to the blood stream. 



Some of the absorbed iron passes into the thoracic duct (Gaule). According 

 to MacCallum and Hall, if the amount of iron given be small, it is absorbed 

 only in the uppermost part of the duodenum; with larger doses its absorption 

 appears to take place in the lower parts of the small intestine, especially in 

 Peyer's patches, and, according to Tartakowsky, almost throughout the entire 

 extent of the gastrointestinal tract. 



We have the following data with regard to the further fate of iron in the 

 body. The iron contained in the body can be split off in part from its com- 

 pounds by certain micro-chemical reactions (treatment with ammonium sulphide 

 and ammonia, or with potassium ferrocyanide and hydrochloric acid) ; another 

 part remains, however, in very stable compounds (e. g., hemoglobin) in which 

 it can be demonstrated only by their decomposition. The iron contained in 

 these compounds represents the real iron stock of the body, other iron being in 

 a state of transition and belonging either to the intake or the output of the 

 body (Hall). 



A part of the absorbed iron is used to renew or increase the supply of iron 

 in the stable compounds, which may have been attacked in metabolism (haemo- 

 globin), a part is stored in the spleen, the liver and the bone marrow. In the 

 spleen iron occurs as an inclosure within the pulp cells (Hall). According to 

 Nesse, the iron compounds of the spleen represent products which have arisen 

 by transformation of red blood corpuscles. The iron-containing substances of the 

 liver are either nucleins (hepatin, Zoleski) or albuminates (ferratin, Schneide- 

 berg), or saltlike compounds (Woltering). 



We have yet much to learn as to the way in which the artificial supply of 

 iron affects the formation of haemoglobin. It is conceivable that the iron 

 is itself used in this formation, but it is also possible that the iron salts circu- 

 lating in the blood stimulate powerfully the blood-forming cells of the bone 

 marrow. 



Even with food entirely free of iron, a regular elimination of this element 

 from the body goes on, chiefly through the bile and through the mucous mem- 



