In some former papers dealing with the study of 

 diphtheria toxins derived from various strains of 



bacilli, we have considered the relation of toxin to 

 antitoxin. 



During the continuation of these researches we have 

 met with a toxin, that is both very remarkable and in 

 many ways very different to the toxins examined be- 

 fore by Ehrlich and Madsen. 



Although the experiments in connection with the 

 thorough analysis of this toxin are not yet completed, 

 we think it of interest to communicate some of the re- 

 sults at the present time, since they are quite in ac- 

 cordance with those obtained in the investigations on 

 Tetanolysin mentioned in the preceding paper. 



The toxin was obtained in the following way: 20 

 litres of bouillon, prepared according to the directions 

 of Dean, were inoculated with a strain of diphtheria 

 culture Park & Williams (No. 8) given to us by Dean. 

 After inoculation the bouillon was left in the incubator 

 at .% for a period of fourteen days ( 15 / 1Q 28 /io 1901). The 

 culture was then removed from the incubator, filtered 

 through ordinary filter paper, bottled with a covering 

 of Toluol and shaken daily for a fortnight. At the end 

 of this time the toxin was quite clear and sterile and 

 has so remained. 



The toxin proved to be very strong. From numer- 



q 



