DIPHTHERIA TOXINE. 71 



slightly poisonous. AKONSON, 1 however, by trituration of the bacilli cells 

 and extraction with ether-alcohol (4:1) followed by extraction with a 

 O'l per cent, solution of ethylene diamine, obtained poisonous extracts 

 from which he could precipitate the poison by means of alcohol. Again, 

 according to BRIEGER and BoER, 2 the extracted cells have certainly a 

 considerable degree of toxicity, but this manifests itself in quite a different 

 manner to the toxine, producing no immunity, &c. 



Diphtheria toxine is thus not a constituent of the cell contents, 

 but a metabolic product. As regards the preparation of diphtheria 

 poison, two things must be sharply differentiated viz., on the 

 one hand, the selection of methods to obtain the largest possible 

 yield of poison, and, on the other hand, the experiments that 

 have been made to isolate specific substances from the toxic 

 cultivations and to investigate their nature, of course with the 

 practical object also in view of obtaining as pure a poison as 

 possible in a dry condition for the purposes of immunisation and 

 serum-therapy. In preparing liquids rich in poison the methods 

 must aim at the two cardinal points of, first, obtaining a solution 

 containing as much poison as possible, and secondly, obtaining 

 this poison as completely as possible in germ-free bouillon, either 

 by sterilisation or separation from the bacilli. 



As regards the production of the toxine, the choice of the 

 nutrient medium is of primary importance. Koux and YERSIN 

 (loc. cit.) and LOFPLER (loc. cit.) cultivated their bacilli on an 

 ordinary meat broth, and so naturally only obtained relatively 

 weak solutions of the poison, especially in the early stages of 

 growth. Subsequently, the addition of 2 per cent, of peptone 

 became the general practice. According to H. KOSSEL (loc. cit.), 

 the nature of this peptone is not a matter of indifference. He 

 had employed with great advantage Dr. Aschmann's peptone 

 from the Luxemburg Hygienic Laboratory. Chapoteaut's 

 peptone has also been found an excellent material. It is 

 also usual to add 0-5 per cent, of ordinary salt, von DuNGERN 3 

 has found it advantageous to add ascitic fluid or to cultivate the 

 bacilli on the fluid itself. 



GUINOCHET 4 asserts that diphtheria toxine is produced even 

 in culture media devoid of albuminous substances. He was 



1 Aronson, "Zur Biologie und Chemie der Diphtheriegiftes," Arch. f. 

 Kinderheilkunde, xxx., 23, 1900 (reprint). 



2 Brieger and Boer, "Ueb. d. Toxine d. Diphtheric, &c.," Deutsch. med. 

 Woch., 1896, 783. 



3 von Dungern, " Steigerung d. Giftproduktion d. Di.-B.," Centralbl. f. 

 Bakt., xix., 137, 1896. 



4 Guinochet, "Contribution a l'e"tude de la toxine des bacilles de la 

 diphtheric," Arch, de Med. Exper., 1892, 487. 



