160 



SECTIONAL ADDRESSES. 



Eilerally, according to the strict derivation of the word 'anoxaemia,' 

 the third type should perhaps be excluded from the category of con- 

 ditions covered by that word, but, as the result is oxygen starvation 

 in the tissues, it will be convenient to include it. Indeed, it would be 

 an act of pedantry not to do so, for no form of anoxaemia has any 

 significance apart from the fact that it prevents the tissues from obtain- 

 ing the supply of oxygen requisite for their metabolic processes. 



The obvious types of anoxaemia may therefore be classified in some 

 such scheme ns the following, and, as it is difficult to continue the dis- 

 cussion of them without some sort of nomenclature, I am giving a name 

 to each type: 



ANOXiEMIA. 



1. Anoxic Type. 



The pressure of oxygen 



in the blood is too low. 

 The haemoglobin is not 



saturated to the normal 



extent. 

 The blood is dark.^, 



Examples : 



1. Rare atmospheres. 



2. Areas of lung par- 

 tially unventilated. 



3. Fluid or fibrin on 

 surface of cells. 



I 



2: Ansemic Type. 



The quantity of functional 



haemoglobin is too 



small. 

 The oxygen pressure is 



normal. 

 The blood is normal in 



colour. 



Examples : 



1. Too little haemo- 

 globin. 



2. CO haemoglobin. 



3. Methaemoglobin. 



3. Stagnant Type. 



The blood is normal, but 

 is supplied to the 

 tissues in insufficient 

 quantities. 

 Examples : 



1. Secondary result of 

 histamine shock. 



2. Haemorrhage. 



3. Back pressure: 



Anoxic anoxaemia is essentially a general as opposed to a local con- 

 dition. Not only is the pressure of oxygen in the blood too low, but 

 the lowness of the pressure and not the deficiency in the quantity is 

 the cause of the symptoms observed. 



Proof of the above statement is to be found in the researches of most 

 workers who have carried out investigations at low oxygen pressures, 

 and it can now be brought forward in a much more convincing way than 

 formerly that oxygen secretion is, for the time at all events, not a 

 factor to be counted with. 



The workers on Pike's Peak, for instance, emphasised the fact that 

 the increase of red blood corpuscles during their residence at 14,000 feet 

 was due to deficient oxygen pressure. No doubt they were right, but 

 the point was rather taken from their argument by their assertion in 

 another part of the paper that the oxygen pressure in their arterial blood' 

 was anything up to about 100 mm. of mercury. Let me therefore 

 take my own case, in which the alveolar pressures are known to be an 

 index of the oxygen pressures in the arterial blood. I will compare my 

 condition on two occasions, the point being that on these two occasions 

 the quantities of oxygen united with the haemoglobin were as nearly as 

 may be the same, whilst the pressures were widely different. 



As I sit here the haemoglobin value of my blood is 96-97, which 

 corresponds to an oxygen capacity of '178 c.c. of O2 per c.c. of blood. 

 In the oxygen chamber on the last day of my experiment, to which I 

 refer later," the oxygen capacity of my blood was '201 c.c. Assuming 

 the blood to be 95 per cent, saturated now and 84 per cent, saturated 



