404 



Mr. W. W. C. Topley. 



From this experiment it is clear that : — 



(1) When no haemolytic antibody is added, haemolysis only occurs in the 

 tube which contains no salt, except the small quantity present in the 

 - 05 c.c. of guinea-pig serum employed as complement. 



(2) When amounts of hemolytic antibody are added below the minimal 

 hsemolytic dose (previously determined for haemolysis occurring in normal 

 saline-saccharose solution), the degree of lysis at first increases as the salt 

 concentration decreases. For instance, while 01 M.H.D. produces only a 

 trace of hemolysis in 08-per-cent. saline it produces moderate haemolysis in 

 the tubes containing 0*56 per cent, to 044 per cent, sodium chloride ; and, 

 while - 5 M.H.D. produces marked haemolysis in the presence of - 8 per cent, 

 sodium chloride, it produces complete haemolysis in the 05-per-cent. solution. 



(3) When, however, the lower concentrations of saline are reached, the 

 anti-complementary factor comes into play and the haemolysis again decreases. 

 The haemolysis in almost all cases reaches its minimum in the tube containing 

 02 per cent, sodium chloride, probably for the reason that this amount of 

 salt is sufficient to prevent or delay the union of red cells and complement, 

 unless a considerable amount of haemolytic antibody is present, while the 

 hypotonicity is sufficiently marked to rapidly destroy the activity of the 

 complement. 



It will be noticed that, although the haemolysis in the great majority of 

 the tubes presents an ordered variation, certain tubes show irregular results ; 

 in the above experiment, for instance, the tube containing 1 M.H.D. in 

 0'72-per-cent. saline and that containing 10 M.H.D. in 02-per-cent. saline. 



Several similar experiments, however, all yielded results agreeing in all „ 

 substantial particulars with those indicated above, though in all there were 

 individual tubes which showed irregular haemolysis. One factor which 

 accounts for this is that the cells tend to sink rather rapidly in the 

 saccharose solution, and sometimes undergo agglutination, while in a few 

 cases the corpuscles show marked agglutination in the saccharose solution 

 before any serum is added, though they remain evenly distributed in control 

 saline tubes. 



Having established the fact that, in passing from markedly hypertonic 

 to markedly hypotonic saline solutions, less and less haemolytic antibody is 

 needed to bring about the union of red cells and complement, and that, when 

 a completely salt-free medium is reached, this union takes place unaided, it 

 seemed necessary to enquire further into the nature of this direct or unaided 

 combination. 



We know that when dealing with a mixture of red cells, haemolytic 

 antibody, and complement, reacting in a medium of normal saline solution, 



