CHAPTER VIII 



THE NATURE OF HEMOGLOBIN SOLUTION 



A.LGERNONBLACKWOOD(i) gives Certain directions as to the way 

 in which an article should be written. You say everything that is 

 worth saying in a line or so at the commencement ; you repeat it at 

 somewhat greater length in the next paragraph or two and finally 

 you make a detailed survey of it in the remainder of the article. This 

 injunction at once relieves me of a considerable difficulty for, before 

 going further, it is necessary to make some preliminary statement as 

 to the nature of what is usually called a "haemoglobin solution," 

 and at the same time it is desirable to defer a final examination of 

 the matter till a later portion of the book. 



Here let us suppose that we have a " solution " of haemoglobin made 

 as indicated in the previous chapter, or even made by simply laking 

 blood, that we have the solution in a closed vessel and that we shake 

 it up with oxygen so as to produce an equilibrium between the 

 haemoglobin and the oxygen, and let us suppose further that we are 

 about to study the nature of this equilibrium; the question must 

 arise: How many phases are involved? We have in the vessel the 

 gas above the liquid, we have the water, and we have the haemoglobin. 

 The water cannot be considered as anything but liquid. Does the 

 gas count as a gas? Does the haemoglobin count as a solid? These 

 questions become the more pertinent because Bayliss(2) has com- 

 pared the equilibrium between oxygen and haemoglobin "solutions" 

 with that between carbonic acid gas and solid calcium carbonate. 



With regard to the oxygen the matter is simply disposed of. It is 

 only the oxygen which is in solution which counts. The gas above the 

 solution is merely a device for obtaining a given concentration of 

 oxygen in the solution. Once the equilibrium is established the atmo- 

 sphere above the solution may be removed, as by intercepting a layer 

 of liquid paraffin between the gaseous oxygen and the solution. No 

 change is wrought in the equilibrium, i.e. in the relation between the 

 oxygen chemically combined with the haemoglobin and that physically 

 dissolved in the water with which the haemoglobin molecules are in 

 intimate contact. 



I have heard the contention that such a treatment of the subject 

 is illegitimate — that the introduction of a layer of paraffin or a glass 



