Metabolic Products 391 



To keep it for experimental purposes it is advisable 

 to precipitate it by supersaturation with ammonium sul- 

 phate, which causes it to float upon the liquid in the form 

 of a sticky brown scum. It can be skimmed oft 7 and dried. 

 Such dry precipitate will retain its activity for months 

 with but little deterioration. 



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. Ehrlich* later discovered a new poison- 

 ous element to which he applied the name tetanolysin. 



The purified toxin of Brieger and Cohn was surely fatal 

 to mice in doses of 0.00000005 gram. The work of these 

 older writers is now so completely superseded by that of 

 others as to be of historic interest only. Lambert f considers 

 the tetanus toxin to be the most poisonous substance that 

 has ever been discovered. 



Fermi and PernossJ found most toxin produced in agar- 

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

 cultures. 



Ehrlich 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. 



D6nitz|| 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 Borreljt have also found that when tetanus 

 toxin is injected into the brain substance a very much 



* "jBerliner klin. Wochenschrift," 1898. 



f "New York Med. Jour.," June 5, 1897. 



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



"Berliner klin. Wochenschrift," 1898, No. 12, p. 273. 



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

 ** "Berliner klin. Wochenschrift," 1898, 35. 

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



