38 QUATERCENTENARY STUDIES IN PATHOLOGY 



aleuron granules and leucocytes, a differential count of which showed, 

 polynuclears 62 %> lymphocytes 22 7o- The mass was frozen and 

 thawed according to Buchner's method, mixed with an equal weight of 

 •85 7o NaCl., and ground with sand in a mortar. It was then 

 centrifuged. The opsonic power of the fluid was then tested along with 

 the serum of the same animal and the serum of a control animal. 

 The result was as follows : — 



Control serum, 5 cocci per leucocyte. 



Serum of aleuronat rabbit, 4 cocci per leucocyte. 



Aleuronat exudate of rabbit, o cocci per leucocyte. 



No opsonin, therefore, was present in the aleuronat exudate in this 

 experiment, but without further experiments of a similar nature it would 

 be unsafe to generalise as to the opsonic content of these leucocytic 

 exudates. 



9. — A Ibumen-metaphosphate. 



In view of the fact that the opsonic index was so markedly influenced 

 by nuclein, it was considered of interest to determine whether the so- 

 called pseudo-nucleins, formed by precipitating albumen solutions with 

 metaphosphoric acid, would produce analogous effects. The method 

 employed for the preparation of the substance was one of the many 

 recommended by Fuld i^^'). To a certain volume of a 10 % solution of 

 Qg^ albumen, an equal volume of a 10 % solution of metaphosphoric 

 acid was added. After filtration the precipitate was suspended in 

 distilled water, and finally centrifuged. The process was repeated for 

 five or six times. The precipitate of albumen-metaphosphate was then 

 dried over sulphuric acid in vacuo, and finely powdered. Of this 

 substance -5 grm., dissolved in 2 7o sodium carbonate, was inoculated 

 intraperitoneally in guinea-pigs and i grm. in rabbits. 



From a long series of experiments we may quote the following, 

 to show that no very marked changes took place in the opsonic index : — 



Exp. I. Guinea-pig. (-5 gm. intraperitoneally at 3 p.m.). 



(358) 



