508 Prof. A. Garngee. On the Behaviour of Oxy -haemoglobin, 



In the absence of all data as to the diamagnetic moment of either 

 Oxy- or CO-haemoglobin, it is impossible to state whether these bodies 

 differ in any degree in respect to their behaviour in the magnetic field. 

 Working carefully but merely qualitatively, it would appear, however, 

 that their behaviour in the magnetic field is identical. 



6. Methcemoglobin is, like Oxy-lmmoglobin, strongly Diamagnetic. 



The substance was prepared by adding to a saturated solution of 

 twice crystallised oxy-haemoglobin of the horse a few drops of solution 

 of ferricyanide of potassium until the characteristic change in colour 

 and in the spectrum indicated the complete conversion into methaemo- 

 globin. The solution was cooled to - 5° C, treated with one-fourth 

 of its volume of absolute alcohol at - 10° C, and the mixture placed 

 in ice and salt for a period of thirty-six hours. The crystalline 

 methaemoglobin which separated was then washed with repeated 

 quantities of ice-cold water, collected on a filter, drained, and dried in 

 vacuo at a temperature not exceeding 5° C. Experiments with lumps of 

 this substance varying in weight between 0'3 and 1*0 gramme showed 

 it to be apparently as diamagnetic as oxy-haemoglobin. 



7. Hcematin and Acethcemin (Hcemin) intensely Magnetic Substances. 

 Preliminary Remarks. 



The more recent analysis of Jaquet, Zinoffsky, and Hiifner have led 

 to the conclusion that, at any rate in the horse, the dog, the ox, and 

 the hen, there exists a remarkable constancy in the proportion of the 

 iron which exists in haemoglobin (0*335 per cent.).* If it be assumed 

 that 1 molecule of haemoglobin contains 1 atom of iron, the molecular 

 weight of the haemoglobin of the dog, the horse, the ox, and the hen 

 would be 16,669, a result which concords admirably with the volume of 

 oxygen and carbonic oxide which can enter into combination with 

 haemoglobin on the assumption (first of all advanced by Lothar Meyer) 

 that 1 molecule of haemoglobin can combine either with 1 molecule of 

 oxygen or of carbonic oxide. The empirical formula for the haemo- 

 globin of the dog calculated by Jaquet from his analyses is probably 

 very near the truth, namely, CrssH^osNigsSsFeC^is- 



Why should haemoglobin possess so enormously high a molecular 

 weight 1 The question suggested itself to Bunge, who has furnished 

 us with a reason which is eminently suggestive : " The enormous size 

 of the haemoglobin molecule," says this writer, "finds a teleological 

 explanation, if we consider that iron is eight times as heavy as water. 



* For a discussion of all the more recent analysis of haemoglobin, see my 

 article on " Hemoglobin " in Schafer's ' Text-book of Physiology/ p. 199, et seg. 



