The same author, in collaboration with Fraenkel,[131] later on isolated a toxalbumin from the culture bouillon of the typhoid bacillus. Sanarelli[132] obtained an active toxin by macerating for several days at 60° C. a month-old culture of the typhoid bacillus made with a 2-per cent. glycerin-bouillon. Chantemesse has also published a process which yields a highly virulent toxin.[133] [131] _Berlin. Klin. Wochenschr._, 1890. [132] _Annal. de l'Instit. Pasteur_, VIII, p. 103. [133] _Compt. rend. Soc. de Biol._, p. 232, Jan. 30, 1897. _Congrès d'Hygiène de Madrid_, 1898. Chantemesse and Widal[134] have shown that on injecting into an organism increasing quantities of the sterilized cultures of Eberth's Bacillus, it is possible to fully immunize an animal against the bacillus itself, and even also against the Bacillus coli communis. The operation, however, is tedious and painful. The serum of immunized animals possesses preventive and curative properties respecting the effects of typhoid bacilli. [134] _Annal. l'Instit. Pasteur_, VI, p. 755; SANARELLI: _Ibid._, p. 721. A dose of the filtered culture, which is fatal to a guinea-pig, becomes innocuous when mixed with 0.5 Cc. of the serum of a vaccinated guinea-pig; 6 Cc. of the serum injected six hours after an injection of the virulent culture, hence when this is in full action, suffice to save the animal.[135] So far as the human being is concerned, the results obtained have not been sufficiently satisfactory. [135] FUNCK: _La Sérothérapie de la Fièvre Typhoïde_, I, Brussels, 1896. The culture bouillon of the Bacillus coli communis, which is closely allied to Eberth's bacillus, also contains soluble toxic substances which have been named coli-bacillus toxin. This substance, which is produced only in small quantity by the microbe, is fatal only in very large doses. =Cholera Toxin.=--Very little is known regarding the toxic products of the spirillium choleræ; nevertheless, the fact that typical cholera exhibits every symptom of the action of a toxic agent demonstrates quite clearly the elaboration of some toxic substance within the cultures of this microbe. Villiers[136] found in it a liquid ptomaine; Klebs[137] found another and crystallizable ptomaine; while Pitai discovered in it a toxin unalterable by heat, and which he considered as a toxopeptone. According to Gamaleia[138] there is present a true toxin, alterable by heat, and the reactions of which entitle it to be considered as a nucleo-albumin; he has also found in it a toxic nuclein. [136] _Compt. rend. de l'Acad. des Sciences_, Jan. 12, 1885. [137] KLEBS: _Allgem. Wien. Med. Zeit._, 1887. [138] _Arch. de Méd. Expérim._, IV, p. 173.