586 APPLICATION OF METHODS OF BACTERIOLOGY 



temperature of the room, or at this temperature in the desic- 

 cator over sulphuric acid, it is not destroyed. 



"Diffuse daylight diminishes the intensity of the poison. 

 Its intensity is preserved when kept in the dark. 



"Direct sunlight robs it of its poisonous properties in 

 from fifteen to eighteen hours. 



" Its activity is not diminished by diluting a fixed amount 

 with water or nutrient bouillon. 



"Mineral acids and strong alkalies lessen its intensity." 



The chemical nature of this poison is not positively 

 known, but according to the observations of Brieger and 

 Cohn^ its designation of "Toxalbumen" is a misnomer, 

 for its reactions do not warrant its classification with the 

 albumins in the sense in which the word is commonly used. 

 When obtained in a pure, concentrated form, its toxic 

 properties are seen to be altered by acids, by alkalies, by 

 sulphuretted hydrogen, and by temperatures above 70° C. 

 Even when carefully protected from light, moisture, and 

 air, it gradually becomes diminished in strength, doubt- 

 less due to the formation of "toxons" and "toxoids," 

 analogous to those observed by Ehrlich in deteriorating- 

 diphtheria toxin. When freshly prepared by the methods 

 of the authors just cited, its potency is almost incredible 

 0.00005 milligrams being sufficient to cause fatal tetanus 

 in a mouse weighing fifteen grams. 



The studies of Madsen^ demonstrate it to consist of two 

 physiologically distinct intoxicating compounds; the one, 

 a solvent of erythrocytes — a "tetanolysin;" the other, a 

 specific irritant which, through its infiuence upon the central 



1 Zeitschrift filr Hygiene and Infektionskrankheiten, 1893, Bd. xv, S. 1. 

 ' Ueber Teanolysin, Zeitschrift fiir Hygiene und Infektionskrankheiten, 

 1899, Bd. xxxii, S. 214. 



