60 Ml' Kencj, On the Idstology of the Blood of Rahhits. [Feb. 27, 



Monday, February 27, 1893. 



Prof. T. McK. Hughes, President, in the Chair. 



The following Communications were made to the Society : — 



(1) On the histology of the Blood of Rahhits which have been 

 rendered immune to Anthrax, by Lim Boon Keng, M.B. (Edin.). 



Abstract. 



The research was conducted in the Pathological Laboratory of 

 the University. The rabbits were rendered immune to anthrax 

 by inoculation with the lymph and blood of frogs which had been 

 subjected to various treatment. Previous observers had succeeded 

 in conferring immunity with the use of similar substances. The 

 object of the investigation, however, was to ascertain the changes 

 in the character and relative number of the Avhite cells of the 

 blood after protective vaccination and after the introduction of 

 virulent anthrax. 



From four to several hours after the injection of the vaccine, 

 a great increase in the number of the white cells is noticeable ; 

 and the most remarkable feature is the augmentation in number 

 of the coarsely granular (eosinophile) corpuscles. The relative 

 proportion in the numbers of the different varieties of cells is 

 therefore altered, so that instead of forming only from 2 to 4 per 

 cent, of the total number of white cells, the eosinophile corpuscles 

 now constitute about 10 to 2.5 per cent. This increase persists 

 only a short time, and on the third day the cells may have 

 returned to a normal condition ; and at this stage hyaline cells 

 ingesting granular cells may be detected in numbers in certain 

 localities. Although the blood has thus apparently returned to 

 the normal condition, it is found that the state of eosinophile 

 leucocytosis is rapidly reproduced, on the introduction of virulent 

 anthrax. After inoculation with a virulent culture of the microbes, 

 the eosinophile cells appear in great numbers, so that they may 

 form 50 per cent, of the white corpuscles, and in one instance an 

 even higher percentage was found. These cells are not only 

 increased in number but are also larger and have larger granules. 

 Similar changes were observed in Guinea pigs rendered immune 

 by Dr Haffkine to the comma bacillus. 



In non-vaccinated rabbits, the introduction of anthrax causes 

 profound leucocytosis, but the cells are all very small and the 

 eosinophile corpuscles are only slightly increased in number. 

 General infection occurs in 36 to 48 hours, rapidly followed by 

 death. 



