586 SAMUEL H. HURWITZ 



bone-marrow, and perhaps elsewhere, and this occurs whether the iron be 

 in intimate organic combination, the so-called food iron, incapable of 

 giving the characteristic microchemical reaction, or whether it be in the 

 form of an organic or inorganic salt of iron (Pearce, Krumbhaar, and 

 Frazier). 



It has been shown by a number of workers (Morawitz(&)) that the 

 amount of iron metabolized in the body so as to be eliminated in the 

 excreta is only a small fraction of the iron ingested in the food or that 

 derived from the disintegration of hemoglobin. The actual figures given 

 by various workers (Lehmann(6), Stockman and Grieg, von Wendt) show 

 some fluctuations. According to Sherman, the body in health eliminates 

 only 7 or 8 milligrams of iron during the fasting state, and on a re- 

 stricted diet from 5.5 to 12.6 milligrams per day, and the amount of 

 food iron required for the maintenance of iron equilibrium in healthy 

 men lies between 6 and 12 milligrams per day. 



Other observers, however, give considerably higher values for total 

 iron excretion. (Table 8.) Kennerknecht, for instance, in normal indi- 

 viduals found the fecal iron alone to average 25 milligrams per day. 

 In the urine only small amounts of iron are eliminated in health. The 

 quantities given by earlier workers vary from 1 to 8 milligrams. But 

 at the present, since the work of Neumann and Mayer, about one milli- 

 gram of iron for a period of twenty-four hours is considered the normal 

 output. 



It is obvious, therefore, that the organism must possess a great power 

 of conserving its iron and of re-utilizing it through some form of inter- 

 mediary metabolism. This phase of the process is little understood, 

 save for the knowledge that the spleen and liver are the great depots 

 for iron storage. The quantity of iron stored in the body and the extent 

 to which the stored iron participates in metabolism are difficult to de- 

 termine. For this reason what knowledge we possess concerning the 

 utilization and elimination of iron both in health and in disease is for 

 the most part based upon determinations of the balance between the 

 amount of iron ingested and the amount excreted. 



The influence of hemorrhage on the elimination and storage of iron 

 has been investigated by some of the earlier workers (Morawitz(fr)). 

 These observations have emphasized certain points of difference between 

 the metabolism of iron in the posthemorrhagic anemias and in those result- 

 ing from blood destruction. Following a loss of blood, the quantity of iron 

 eliminated has been found to decrease; whereas, in the hemolytic anemias 

 the urinary iron excretion usually increases. Furthermore, hemorrhage 

 results in a lessened iron storage in the liver and spleen, while in the 

 hemolytic anemias more than the normal quantity of iron is stored in 

 these organs. Thus, William Hunter in a study of the intermediary iron 

 metabolism in these two conditions noted an average of 19 milligrams of 



