438 BACILLUS BOTtlLINUS 



Immunity. Malignant oedema was one of the first diseases 

 against which immunity was produced by injections of toxins. 

 The filtered cultures of the bacillus in sufficient doses produce 

 death with the same symptoms as those caused by the living 

 organisms, but a relatively large quantity is necessary. Chamber- 

 land and Koux (1887) found that if guinea-pigs were injected 

 with several non-fatal doses of cultures sterilised by heat or freed 

 from the bacilli by filtration, immunity against the living 

 organism could be developed in a comparatively short time. 

 They found that the filtered serum of animals dead of the 

 disease is more highly toxic, and also gives immunity when 

 injected in small doses. These experiments were confirmed 

 by Sanfelice. 



Methods of Diagnosis. In any case of supposed malignant 

 oedema, the fluid from the affected tissues ought first to be 

 examined microscopically, to ascertain the characters of the 

 organisms present. Though it is not possible to identify ab- 

 solutely the bacillus of malignant oedema without cultivating it, 

 the presence of spore-bearing bacilli with the characters described 

 above is highly suspicious (Fig. 126). In such a case the fluid 

 containing the bacilli should be first exposed to a temperature 

 of 80 C. for half an hour, and then a deep glucose agar tube 

 should be inoculated. In this way the spore-free organisms are 

 killed off. Pure cultures may be thus obtained, or this procedure 

 may require to be followed by the roll-tube method under 

 anaerobic conditions. An inoculation experiment, if available, 

 may also be made on a guinea-pig. 



BACILLUS BOTULINUS. 



The term " meat-poisoning " embraces a number of conditions 

 produced by different agents, and the relation of the bacillus of 

 Gaertner to one class of case has already been discussed. Another 

 group was shown by van Ermengem in 1896 to be caused by an 

 anaerobic bacillus to which he gave the name bacillus botulinus. 

 He cultivated the organism from a sample of ham, the inges- 

 tion of which in the raw condition had produced a number of 

 cases of poisoning, some of them followed by fatal result. The 

 symptoms in these cases closely corresponded with those occur- 

 ring in the so-called " sausage poisoning " met with from time to 

 time in Germany and other countries where sausages and ham 

 are eaten in an imperfectly cooked condition. Such cases form 

 a fairly well-defined group, the symptoms in which are chiefly 

 referable to an action on the medulla, and, as will be detailed 



