'^()8 LOCAL TISSUE REACTIVITY 



Ultraxiolet radiation destroys most of the true toxins (Louen- 

 slein, 1914; Hortotk. Sdunnian and Stiner, 1914) . In a recent 

 investigation Welch (hjj^o) was able to detoxify tetanus toxin by 

 means of ultraviolet light provided the toxin was sufficiently 

 diluted to remove the protein absorjjtion factor. Toxin having an 

 M.L.D. of 1 '52 of 1 c.c. \vas not destroyed by ten minutes' ex- 

 posine. whereas toxin diluted four times (M.L.D. 18 c.c.) was 

 completely destroyed in two to four minutes. This author also 

 reported the detoxification of active principles of B. coli and 

 B. typJwsus cultures by ultraviolet radiation. 



In previous years the true toxins were considered so]id)le 

 bacterial jiroducts obtained imder conditions of insignificant cell 

 autolysis. R(nix and Yersin beliexed that dij:)iitlieria toxin was a 

 product of secretion of bacilli given up dining the stages of 

 gro^vtli. In 1904. Mmillo, however, observed considerable toxic- 

 ity in the bacillary bodies. Later Fukutaki (1924) came to the 

 conclusion that a large amoimt of toxic substances may be ex- 

 tracted from dried diphtheria bacillary bodies. There seems to 

 be no question as to the identity of the broth toxins and the 

 toxic substances derived from the l:)acilli, inasmuch as the extracts 

 produce specific jjathological lesions, and their effect is neutral- 

 ized by diphtheria antitoxin. The identity of the diphtheria endo- 

 and exotoxins Avas fiuther corrol^orated by xarioirs authors. Eisler 

 and K()\acs (1926) demonstrated that the greatest portion of toxin 

 may be olitained in the first washing of the tetanus bacillus. An 

 important contribution to the subject ^vas recently made by 

 Prigge (1932), \vho also foimd that the dead bacillary bodies 

 washed several times in physiological saline produce symptoms 

 of intoxication similar to diphtheria toxin provided toxigenic 

 bacilli are employed. The toxic substance of the bacillary l)odies 

 is specifically neutralized by diphtheria antitoxin and is identical 

 with the toxin obtained in fluid cidtmes. Centrifuged and fil- 

 tered washings of diphtheria bacilli in physiological saline con- 

 tain considerable amoiuits of toxin. Repeated washings at short 

 intervals of time remove most of the toxin from the bacilli. If 

 the washed bacilli are left standing for a few days, an additional 

 amount of toxin may be removed by washing. This author con- 

 cludes that a toxin represents a constituent of the bacillary body 

 which is given off into the surrounding medium after its death. 

 It is obvious, therefore, that ^^•hilst the soluble diphtheria toxin 

 is easily given off into the smroimding mediimi, a considerable 



