182 TOXINES AND ANTITOXINES. 



either in a state of free secretion or as an endotoxine retained by 

 the cells, has not yet been adduced, and the existence of an 

 endotoxine is practically disproved. With the exception of 

 substances causing slight pyrogenic effects due to the bacterial 

 proteins of the cell itself and similar to those produced by all 

 bacteria, whether pathogenic or harmless, no anthrax poisons are 

 known. At the same time we must assume that poisons that 

 cause the symptoms of the disease are formed ; yet these appear 

 to be of such a subtle character and to be produced so sparingly 

 during the growth of the bacilli in the attacked organism as to 

 escape detection. COXRADI made no experiments with regard 

 to the immunising power of his sterile nitrates ; and it is 

 conceivable that they contained toxoids which had immunising 

 capacity but were no longer toxic, and that this is a possible 

 explanation of HANKIN'S results. These obvious possibilities 

 still remain unsettled. 



OTHER SOLUBLE BACTERIAL POISONS POSSIBLY OF 

 THE NATURE OF TOXINES. 



When we consider that the investigation of the specific poisons 

 of some of the most important pathogenic micro-organisms is for 

 the most part still in its infancy, it is not surprising that, in the 

 case of less important bacteria, we have very scanty results, to 

 which I will only briefly refer here. It is quite possible that on 

 closer investigation one or more true toxines may still be dis- 

 covered as a product of these bacteria, but as yet there are no 

 certain indications of this. 



As regards the majority of those infectious bacteria that grow 

 within the organism, we can come to the same conclusion as in 

 the case of cholera, streptococci, <fcc. viz., that if the cells secrete 

 any true toxines they do so only in minute quantities, that these 

 are extremely unstable, and that the poisons must be regarded 

 as consisting in the main of firmly retained endotoxines. Im- 

 munity, as in the case of all infectious micro-organisms, is 

 brought about almost exclusively by bacteriolytic processes, 

 any eventual formation of antitoxine being insignificant and 

 occupying an altogether inferior position, both from the practical 

 and theoretical point of view. 



HOG CHOLERA. 



METSCHNIKOFF l and also SELANDER 2 found the sterilised 



1 Metschnikoff, "Zur Immunitatslehre," Congr. /. inn. Med., 1892, 282; 

 "Etudes sur 1'immunite," Ann. Past., v. ; vi., 2S9, 1892. 



2 Selander, "La maladie infectieuse des pores.," Ann. Past., iv., 545, 

 1890. 



