Toxic Products 401 



stroyed by heat above 6o-65 C. It is also decomposed by 

 exposure to the air and light, so that it is difficult to preserve 

 it for many days. The best method of keeping it is to add 

 0.5 per cent, of ph nol, and then store it in a cool, dark place, 

 in bottles completely filled and tightly corked. It will not 

 keep its strength in liquid form under the best conditions. 



To keep it for experimental purposes it is advisable 

 to precipitate it by supersaturation with ammonium sul- 

 phate, which causes it to float in the form of a sticky brown 

 scum upon the liquid. It can be skimmed off and dried. 

 Such dry precipitate will retain its activity for months 

 with but little deterioration. 



Fermi and Pernossi * found most toxin produced in agar- 

 agar cultures, less in gelatin cultures, and least in bouillon 

 cultures. 



Ehrlich f found two poisons in the tetanus toxin, one of 

 which was convulsive and was in consequence called tetano- 

 spasmin, the other hemolytic and called tetanolysin. When 

 tetanus toxin is added to defibrinated blood, the tetano- 

 lysin is absorbed by the corpuscles, many of which are 

 dissolved, while the tetanospasmin remains unchanged. 



Donitz t and Wassermann and Takaki have found that 

 the tetanus toxin has a specific affinity for the central 

 nervous system, with whose cells it combines in vitro and 

 becomes inert. 



Roux and Borrel|| have also found that when tetanus 

 toxin is injected into the brain substance a very much 

 smaller dose will cause death than is necessary when the 

 poison is absorbed from the subcutaneous tissues. 



From cultures of tetanus bacilli grown in various media, 

 and from the blood and tissues of animals affected with the 

 disease, Brieger succeeded in separating "tetanin," "tetano- 

 toxin," " tetanospasmin," and a fourth substance to which 

 no name is given. All were very poisonous and productive 

 of tonic convulsions. Later Brieger and Frankel isolated an 

 extremely poisonous toxalbumin from sugar-bouillon cul- 

 tures of the bacillus. 



The purified toxin of Brieger and Cohn was surely fatal 



*"Centralbl. f. Bakt.," etc., xv, p. 303. 

 t "Berliner klin. Wochenschrift," 1898, p. 273. 

 t "Deutsche med. Wochenschrift," 1897, p. 428. 

 "Berliner klin. Wochenschrift," 1898, 35. 

 !| "Ann. de 1'Inst. Pasteur," t. xn, 1898. 

 26 



