ADRENAL INSUFFICIENCY AND BLOOD-DISINTEGRATION. 113 



As already stated, acids disintegrate haemoglobin, haematin 

 being formed. This only occurs, however, in the presence of 

 oxygen. In the lungs, therefore, the "loose combination" in- 

 volving imperfect absorption of oxygen, while defective res- 

 piration is further encouraged by the imperfect or arrested 

 action of the respiratory muscles, the process of haemoglobin 

 disintegration, if at all influenced, is rather interfered with 

 than encouraged. It is consequently not in the respiratory area 

 that the process occurs, and, if elsewhere in the organism, the 

 reaction must be one in which oxygen is absent. We have 

 already seen, when chlorosis was studied, that, when haemo- 

 globin is treated with an acid in the absence of oxygen, a 

 ha?mochromogen first appears which slowly loses its iron, the 

 end-product being hsematoporphyrin. What was then said, 

 therefore, is also appropriate in connection with the process 

 through which haamatoporphyrin is formed: i.e., the tissues 

 play the part of the acid employed in the laboratory to disintegrate 

 hcemoglobin: they abstract its oxygen. The imperfect condition 

 of the blood involving reduced oxidation, oxyhcemoglobin is not 

 always formed, and arterial blood fresh from the lungs, while still 

 containing enough of this compound to more or less perfectly carry 

 on the vital processes, also contains a more or less great proportion 

 of free hcemoglobin. Under these conditions, the avidity of the 

 tissues for oxygen causes them not only to absorb the one molecule 

 of this gas from the oxyhazmoglobin, but also to make up for the 

 deficiency by taking up oxygen from hcemoglobin: i.e., the only 

 remaining source of supply. We thus have in the blood the precise 

 conditions required for the reaction outlined, namely: absence of 

 oxygen and a powerful reducing agent, the tissues, and, there- 

 fore, obtain as end-results free iron and hwmatoporphyrin. 



This suggests another query. The microscopical examina- 

 tions of adrenals taken at random at autopsies have shown 

 Arnaud that 36 per cent, of all adrenals contain evidences, more 

 or less marked, of fatty degeneration. Why, under these cir- 

 cumstances does haBmatoporphyrinuria, which may be induced 

 by a large number of toxic disorders, not appear more fre- 

 quently? The answer is readily available: hcematoporphyrin. 

 bilirubin, iron-free hcematin, and haemato'idin are isomers: i.e., 

 the same body is now recognized under different names. 



