ENDOTOXINS 45 



Handbuch der landwirtschaftlichen Bakteriologie (Borntraeger, 

 Berlin, 1910, full bibliography). On Bacterial Products, see 

 Cellular Toxins, by Vaughan and Novy, 1902 (Bibliog.), Ueber 

 Ptomaine, by Brieger, 1885 ; Macfadyen, The Cell as the Unit of 

 Life (Churchill, 1908) ; Wells, Chemical Pathology, Ed. 3, 1917 ; 

 Hewlett, Art. " Toxins and Antitoxins," Thorpe's Diet, of 

 Chemistry, 1913. For General Bibliography, see Kolle and 

 Wassermann, Pathogenen Mikroorganismen, Ed. 2, 1913. 



Endotoxins 



The majority of pathogenic micro-organisms do not excrete any 

 appreciable amount of toxin ; the toxin remains within the cells. 

 To such an intra-cellular toxin the name of " endotoxin " has been 

 given. The toxins of the staphylococci and streptococci, the 

 typhoid-colon group, plague, cholera, etc., are endotoxins. 

 Various methods have been employed to prepare these endotoxins, 

 such as extraction of the cells by the action of weak alkalies and 

 enzymes, and by autolysis or self-digestion. 



The late Dr. Allan Macfadyen conceived that if the intra- 

 cellular toxins (endotoxins) of such organisms as the typhoid 

 bacillus, cholera vibrio, etc., could be obtained free from the 

 bacterial cells, it might be possible to prepare sera (anti-endotoxic 

 sera) of much more therapeutic potency than the ordinary anti- 

 microbic sera. 



The disintegration of the bacterial cells in the presence of intense 

 cold, to prevent chemical change in the bacterial juice obtained, 

 was the method devised by Macfadyen to attain this end. With 

 the aid of his colleagues, Mr. Eowland and Mr. Barnard, and of his 

 laboratory assistants, Messrs. Burgess and Thompson, apparatus 

 and methods were evolved to effect this. 



By growing on the surface of agar or other suitable medium in 

 plate bottles (Fig. 19), scraping off the growth and suspending 

 this in salt solution, centrifuging at high speed, and collecting 

 the bacterial cell-mass on the walls of the centrifuge vessels, 

 sufficient material is readily obtained to grind or triturate, and 

 thus disintegrate the bacterial cells so as to liberate their contents. 

 This is accomplished by means of a special machine, the essential 

 part of which consists of a metal cone revolving at a high speed 

 in a metal pot, the bottom of which is shaped so as to fit the cone. 



