I 



Artificial immunity against toxins 353 



plienomenon of hyperleucocytosis is one of the most striking 

 manifestations of a positive chemiotaxis in white corpuscles. It is 

 true that, as to this reaction during the course of vaccination, the 

 views of observers are not unanimous. Besredka^ as the outcome of 

 his work on this subject, expresses himself very distinctly. "During 

 the course of an immunisation against diphtheria toxin," he writes, 

 "one always observes a marked reaction in the goat, either at the 

 beginning or at an advanced stage of the period of injections and 

 especially in the first few hours after injection '' (p. 322). Nicolas and 

 Courmont^ in their first memoir maintain that hyperleucocytosis 

 "is not necessary for immunisation." Nevertheless, in the de- 

 scription of their experiments, which were performed on horses 

 vaccinated against diphtheria, it is clear that the number of white 

 corpuscles is often markedly increased. Further, in several cases 

 they describe the formation of tumours at the point of inoculation, [371] 

 some of which end in suppuration. Under these conditions, it is not 

 possible to deny a vaccinal reaction on the part of the leucocytes. 

 Later, Nicolas, Courmont and Prat^ published a second memoir on 

 the same subject, in which they seek to confirm their view of the 

 uselessness of hyperleucocytosis in vaccination against the poison of 

 diphtheria. They give details of experiments on several species of 

 animals and insist specially on the conditions in which they have not 

 observed hyperleucocytosis. " The doses from the first have always 

 been extremely weak and with the addition of Lugol's solution to 

 attenuate them ; only very gradually have we reached stronger doses, 

 as that is one of the indispensable conditions for the avoidance of 

 leucocytic variationSy whilst obtaining a good and rapid immunisa- 

 tion" (p. 974). These special precautions to avoid hyperleuco- 

 cytosis demonstrate clearly that this phenomenon is usually pro- 

 duced during the course of vaccination. It is quite natural 

 that we should, by proceeding very slowly and with small doses 

 of toxin, succeed in diminishing or even suppressing the afflux 

 of leucocytes ; but this fact cannot in any way minimise the im- 

 portance of the leucocytic reaction in vaccination. In these particular 

 cases, this reaction may take place without the number of leucocytes 

 in the blood being noticeably increased. In reading the details of 

 the experiments made by the Lyons observers, it will be seen that, 



1 Ann. de VInst. Pasteur^ Paris, 1898, t. xii, p. 318. 



^ Arch, de med. exper. et d^anat. path., Paris, 1897, t. ix, p. 770. 



2 Journ. de physlol. et de path, gen., Paris, 1900, t. ii, p. 973. 



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