The specific oxygen capacity of blood 11 



The above experiments were all made upon the blood of animals 

 in good health, or at all events not known to be in bad health. 



Now that the physiological problem may be regarded as settled 

 the pathological ones remain, and become the more ripe for settle- 

 ment. These offer quite distinct subjects from that which we have 

 discussed, inasmuch as there may be intermediate bodies present 

 which are being worked up into haemoglobin in the blood, or degene- 

 rate substances such as methaemoglobin. One aspect of these 

 problems resolves itself into an investigation of whether the oxygen 

 capacity and the colour go hand in hand in the case of anaemic 

 patients a most important consideration for the only real use of 

 the haemoglobinometer is as an index of the oxygen carrying power 

 of the blood. According to Morawitz (13) they do. 



I will not enter upon a discussion of what really can only be 

 settled by accurate analysis. 



In the meantime it is clear that in doubtful cases the haemo- 

 globinometer may be put on one side and the oxygen capacity of the 

 blood measured directly. The following is a case in which this has 

 been done. The oxygen capacity of the blood was observed systemic- 

 ally throughout the case by actual oxygen determinations, each of 

 which was carried out upon one-tenth of a cubic centimetre about 

 two drops of blood, with results which inspire complete confidence. 

 This direct procedure obviated all assumptions as regards specific 

 oxygen capacity of pathological blood. The case was one of so-called 

 biliary fever in the horse investigated by Nuttall and Strickland (U) in 

 the Quick Laboratory at Cambridge. The object was amongst other 

 things to determine the oxygen capacity of the blood whilst it was 

 suffering from the ravages of the blood parasite Nuttallia equi. 

 This parasite makes its home in the red blood corpuscles. The 

 stages of its development are shown in Fig. 2, the description of 

 which I quote from Nuttall and Strickland's paper. 



"N. equi multiplies slowly and in the following manner : 



(1) The minute piriform or oat-shaped parasite enters a fresh 

 corpuscle and (Fig. 2 ; 2, 3, 4, 5) grows in size, being slightly 

 amoeboid, with a general tendency to resume a pear shape. Definitely 

 amoeboid movements (6) are, however, only to be seen distinctly when 

 the parasite has attained a certain size. Judging from the form of the 

 chromatin masses, stages 7, 8, 9, 10 follow next. The rest of the cycle 

 has been continuously observed in the living parasite : the formation 

 and breaking-up of the cross-form, the scattering of the daughter 

 cells within the corpuscle, and their escape from the corpuscle " 



