1909.] 



Hcem -agglutinins, etc., in the Blood. 



209 



It has been noted in these experiments that when the immune serum 

 causes haemolysis of normal red cells that the cases are of the severe toxic type 

 and terminate fatally. It is true that the number of cases investigated is 

 too small to lay too much emphasis on this observation, but it is unquestion- 

 ably important. 



In the first case, immune serum caused marked haemolysis in the presence 

 of normal red cells. A gradual diminution in the reaction occurred from the 

 mixture which contained 75'0 per cent, of serum down to thai which had a 

 serum content of 25 - per cent., and in one instance 12 - 5 per cent. In the 

 second case, which terminated fatally, an exactly similar result was noted ; 

 in the third case, the blood examined a few days before death and that 

 obtained at the post-mortem examination gave a similar result, with the 

 exception that the serum obtained during life had a slightly greater potency. 



In the remaining cases in which haemolysis occurred, it was due to the 

 action of normal serum on the immune red cells, and the reaction took place 

 with about the same serum content as with the immune serum and normal 

 red cells in the fatal cases. In all the experiments immune serum and 

 immune red cells failed to react ; in fact, no other type of haemolysis occurred 

 beyond that referred to. 



The blood of a case of paroxysmal haemoglobinuria has been examined 

 during the acute attack and during the interval. The blood drawn from the 

 finger in the usual way failed to show tinging of the serum with haemoglobin 

 when the usual precautions were adopted. It can be stated briefly that 

 during the height of an acute attack, which is caused by severe cold, that 

 the blood undergoes auto-haemolysis, but when tested as the attack subsides, 

 although the man is obviously ill, no auto-haemolysis can be demonstrated. 

 The immune serum also fails to haernolyse normal red cells, although it 

 agglutinates them strongly, and the immune urine fails to haernolyse the 

 immune red cells. When, however, normal serum is added in definite 

 measured volumes to the immune red cells, haemolysis occurs, although not 

 to any very great extent, and haemolysing agglutinins can be similarly 

 demonstrated. It would seem that the red cells themselves are principally 

 affected — a point still further illustrated by the phagocytic experiments to 

 be subsequently referred to. The blood of two cases of diabetic coma 

 obtained after death failed to haernolyse the immune red cells, but, as in the 

 fatal cases of typhoid fever, haemolysed normal red cells and agglutinated 

 them strongly ; in each instance haemolysis occurred down to a serum content 

 in the mixture of 37'5 per cent. 



Splenic Extract. — Owing to observations made on the splenic cells in 

 certain diseases in which much phagocytosis of red cells occurs, it suggested 



