#98 



0PS0NISATI0N FROM A BACTERIAL POINT OF VIEW, ETC., 



the opsonins, the complement is not destroyed at 60°, but is only 

 slowed in its action. The experiment, however, clearly shows 

 that in antituberculous serum there are latent opsonins. 



Compared with normal serum, the latent opsonins were small 

 in amount, but it must not be forgotten that the experiment 

 may only have shown the action of a small portion of the total 

 quantity. It may be that a much greater amount is rendered 

 active in vivo. 



The influence of clotting upon the production of opsonins. — 

 In obtaining serum, the blood is as a rule allowed to lie for some 

 time to allow of the formation of a clot and the separation of the 

 serum. With short intervals of time, say from one to six hours, 

 there is no diminution of the opsonic content at ordinary tempera- 

 tures. It is, however, not known if the opsonins of the serum 

 suffer any diminution or augmentation while lying in contact 

 with the clot. If we go by the ideas of the Metchnikoff school 

 that the immune bodies are derived from leucocytes and are 

 liberated only upon their destruction, we should expect that 

 contact with the clot should cause the transference of an increased 

 quantity of immune bodies into the serum. Possibly this might 

 apply to the opsonins, and to see if such really did occur the 

 following experiments were made. 



Serum centrifugalised 5-7 min. after drawing 

 the blood 



Serum centrifugalised 30 min. after drawing 

 the blood 



Cocci per leucocyte. 



a 



12-2 

 10-6 



9 3 

 7 5 



74 

 9 



Blood centrifugalised immediately after draw- 

 ing; plasma allowed to clot and serum 

 separated . 



The same serum 30 min. after 



Serum from blood clot, 30 min. after drawing 



101 



9-5 



13-3 



129 



9'2 



9-9 



10-2 



d 



8-6 

 8-4 

 8-9 



The results are too conflicting to lead us to believe that there 

 is any difference in the opsonic content of the serum when 



