DIPHTHERIA TOXINE. 81 



It is very sensitive to external influences. The true toxine is 

 very rapidly destroyed by boiling and fairly rapidly at about 

 60 C., but the heated solution still retains a certain toxic power, 

 and when injected into animals produces emaciation and paralysis 

 as a secondary affection, and frequently causes death. The 

 poison appears to undergo a similar change within the organism. 

 Roux and YERSIN have prepared poisonous substances with 

 quite analogous properties from the organs and urine of children 

 who had suffered from severe attacks of diphtheria. These 

 produced toxic effects resembling those caused by toxones (vide 

 infra). 



The simultaneous action of oxygen and light injure diphtheria 

 toxine very rapidly, but either of the factors alone has much less 

 effect. 



According to PIAZZA/ diffused daylight acts very slowly ; a perceptible 

 decrease can be observed after twenty-three days, but it does not become 

 considerable until after ninety- six days. Direct sunlight acts very ener- 

 getically when oxygen is admitted. Only the ends of the spectrum, the 

 heat rays, and the actinic rays (red and violet) have any action, the centre 

 (yellow) being completely inactive. 



The toxine is also rendered inactive by acids. Roux and 

 YERSIN state that acidification of a solution of the poison with 

 lactic or tartaric acids renders it nearly harmless ; phenol, boric 

 acid, and borax have a less injurious effect. Neutralisation par- 

 tially restores the activity. 



According to BRIEGER and BOER, it is extraordinarily sensi- 

 tive to the action of oxidising agents, whereas reducing agents in 

 slightly alkaline solution have but little effect. This explains 

 why the slightly alkaline reducing fluids of the body form its 

 best medium. DELEARDE 2 asserts that it is rendered innocuous 

 by antipyrine. It is also destroyed by other antiseptics when 

 more concentrated, and by salicylaldehyde (SALKOWSKI 3 ). Yeast 

 weakens the toxine (NOBECOURT 4 ). 



It is extremely probable that, in general, the nature of the 

 surrounding medium has an influence upon the condition and the 

 action of the toxine, but it is far too sweeping, and is contra- 



1 Piazza, "Influenza della luce solare sullatossina difter.," Ann. d'Igiene 

 Sperim. [New Series], v., 521, 1895; Abst. Centralbl. f. Bah., xix., 914, 

 1896. 



2 De"14arde, " Rech. expe"r. sur les proprie'te's, &c., de 1'antipyrine," 

 Arch. de. Med. Exper., 1897, 786. 



3 Salkowski, " Ueb. d. Wirkg. d. Antiseptica auf Toxine," Berl. Uin. 

 Woch., 1898, 545. 



4 Nobe'court, "Action des levures, &c,," Soc. BioL, Hi., 753, 1900. 



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