BY R. GREIG-SMITH. 697 



reaches a maximum which is maintained while the serum is being 

 given. The rise is in some cases coincident with an improvement 

 in the general condition of the patient. The action of the serum 

 might be explained by the serum containing an excess of opsonins, 

 but as it only gives an index of 0*127 some other explanation 

 must be found. 



I have already shown* that heat only retards or slows the 

 action of staphylopsonin, and age may have the same action upon 

 the tuberculopsonin in Marraoreck's serum. This was tested in 

 the following manner. Equal volumes of Marmoreck's serum 

 and a suspension of dead B. tuberculosis in 06% saline were 

 heated at 37° for 20 hours when a third volume of corpuscles 

 was added and the phagocytic index determined in the usual 

 manner. A control quantity of serum was heated at the same 

 time at the same temperature after which the corpuscles and the 

 bacterial suspensions were added. 



Cocci per leucocyte. 



Serum in contact with bacteria for 20 hours 1 16 



Control 015 



The bacteria in the control were isolated while those in the 



contact test were agglutinated. To avoid this agglutination 



another test was made in which the bacteria was suspended in 



0*1% saline. 



Cocci per leucocyte. 



1. Serum in contact with bacteria for 20 hours 2 4 



2. Serum in contact with bacteria for 44 hours 1 *6 



3. Control serum incubated for 20 hours 0*0 



4. Normal serum (15 min contact) 7'9 



In No. 1 there were a few clumps in the films and in the leuco- 

 cytes enumerated there were three which contained four clumps 

 comprising 37 bacteria. Clumps were absent in Nos.3 and 4. 

 In No. 2 the bacteria had largely disappeared, and most of the 

 remainder, including those which had been phagocytosed, stained 

 faintly, showing clearly the action of the immune bodies. It 

 would have been useless to endeavour to destroy the complement 

 by heating the serum at 60°, for I have already shown that, like 



* These Proceedings, 1905, p. 550. 



