MICROSCOPICAL AND CULTURAL CHARACTERS 453 



30 C. ; at the body temperature growth is slower and less 

 abundant and spore formation does not occur. 



Pathogenic Effects. Like the tetanus bacillus, the bacillus 

 botulinus has little power of flourishing in the tissues, whereas it 

 produces a very powerful toxin. Van Ermengem found that the 

 characteristic symptoms could be produced in certain animals 

 by administering watery extracts of the infected ham or cultures 

 either by the alimentary canal or by subcutaneous injection. 

 Here also there is a period of incubation of not less than six to 

 twelve hours before the symptoms appear, and when the dose is 

 small a somewhat chronic condition may result, in which local 

 paralyses form a striking feature. The characteristic effects can 

 also be produced by means of the filtered toxin by either of 

 the methods mentioned, though in the case of administration by 

 the alimentary canal the dose requires to be larger. Here also, 

 as in the case of the tetanus poison, the potency of the toxin is 

 remarkable, the fatal dose for a guinea-pig of 250 grm. weight 

 being in some instances '0005 c.c. of the filtered toxin. In cases 

 of poisoning in the human subject, the effects would accordingly 

 appear to be produced by absorption of the toxin from the 

 alimentary canal; it is only after or immediately before death 

 that a few bacilli may enter the tissues. Van Ermengem 

 obtained a few colonies from the spleen of a patient who had 

 died from ham-poisoning. The properties of the botulinus toxin 

 have been investigated, and have been found to correspond 

 closely, as regards relative instability, conditions of precipitation, 

 combination with sensitive cells (i.e., of brain and cord), etc., 

 with the toxins of diphtheria and tetanus. An antitoxin has 

 also been prepared by Kempner by the usual methods, and has 

 been shown not only to have a neutralising property, but to 

 have considerable therapeutical value when administered some 

 hours after the toxin. The subject has been studied by Leuchs, 

 and he has found that the combination toxin-antitoxin can 

 be split up by the action of acids and the two components 

 recovered, just as Morgenroth showed to occur in the case of 

 diphtheria (p. 566). The direct combining affinity of the toxin 

 for the central nervous system has been demonstrated by Kempner 

 and Schepilewsky by the same methods as Wassermann and 

 Takaki employed in the case of the tetanus toxin. The condition 

 of the nerve cells in experimental poisoning with the botulinus 

 toxin has been investigated independently by Marinesco and by 

 Kempner and Pollack, and these observers agree as to the 

 occurrence of marked degenerative changes, especially in the 

 motor cells in the spinal cord and medulla. Marinesco also 



