386 LECTURE XVII. 



The above tables are of interest in another respect. They show that 

 the iron stores of the suckling plus the amount of iron in the milk are, 

 towards the end of the period of lactation, no longer sufficient for the 

 formation of the required amount of hemoglobin. The organism is evi- 

 dently in a state of iron starvation. As soon as fodder rich in iron is 

 taken into the system together with the milk, the hemoglobin values 

 increase rapidly. This shows how undesirable it is that the human off- 

 spring should be restricted to a milk diet much longer than the ordinary 

 period of lactation (7 to 9 months). The child then requires more iron 

 in its food. 



Iron has, from days of antiquity, always been considered as playing an 

 especially important part in the nourishment of the human organism, 

 and chiefly on account of the pathological condition known as chlorosis, 

 or green sickness. This occurs particularly in young women at, or near, 

 the age of puberty. The name is derived from the peculiar, character- 

 istic, greenish-yellow colored skin of such patients. It was early rec- 

 ognized that this most prominent symptom together with the paleness 

 of the mucous membrane was to be traced to anaemia, an impover- 

 ishment of the blood. The disease has always been combated by pre- 

 scribing iron. On examining the blood of those suffering from this disease, 

 it is found that there is a deficiency in the amount of hemoglobin per 

 unit of volume. It is not, as in forms of anaemia caused by loss of blood, 

 or otherwise, due to the fact that the total number of blood corpuscles is 

 diminished and consequently the hemoglobin content, but rather that 

 the amount of hemoglobin contained in the individual corpuscles is too 

 small. While in many cases the actual number of red corpuscles remains 

 normal, still it often sinks considerably. The only interest that this 

 disease has for us at this place is to the extent that the study of it, and 

 particularly of the therapeutic action of iron, has cleared up the question 

 concerning the absorption and assimilation of this metal and of the other 

 inorganic elements which are required by the organism. The fact that 

 inorganic iron salts have a favorable action upon chlorosis has been known 

 for a long time. How the iron acted was not known, it was merely 

 taken for granted that it was absorbed and assimilated; i.e., utilized for 

 the formation of hemoglobin. This view was perfectly plausible as long as 

 nothing definite was known concerning the manner in which the iron is 

 held combined in the hemoglobin molecule. If the hemoglobin merely 

 contains the iron in a loose, salt-like state of combination, it would be 

 perfectly plausible to think of an assimilation of inorganic iron salts. It 

 is now known, however, that the iron contained in hematin, a compound 

 very closely related to hemoglobin, is in a very firm state of combination. 

 It resists the action of boiling, concentrated potassium hydroxide and 

 boiling hydrochloric acid. By dissolving it in concentrated sulphuric 



