M2 MICROBES AND TOXINS 



influence of a suitable dose of alcohol; an intracerebral 

 injection which kills the sensitive control leaves the 

 narcotised guinea-pig unharmed.^ 



In practice intracerebral injections have supplied Besredka 

 with a useful means of measuring the toxicity of a serum, for 

 example, anti-diphtheria serum, from the point of view of the 

 symptoms of serum sickness. Should a method be discovered 

 of diminishing or destroying the toxicity of sera, the improve- 

 ment acquired could thus be estimated. In particular, the 

 method will tell us whether a serum may be safely injected by 

 the route by which it manifests its greatest toxicity, but also its 

 greatest efificacy, i.e., intravenously. Experience has shown 

 that a serum, very toxic the day of the bleeding (minimum 

 lethal dose -^ c.c), rapidly loses this toxicity during the ten 

 days following (lethal dose /^ c.c). It continues to diminish 

 slowly, for a month and a half, but after about two months it 

 remains almost indefinitely at the same level (lethal dose |^ c.c), 

 and never becomes non-toxic For example, a sample of 

 serum kept in Roux's laboratory for thirteen years still kills 

 sensitive guinea-pigs in a dose of ^ c.c. intracerebrally 

 (Besredka). 



Antianaphylaxis. — Anaphylaxis is a morbid state predis- 

 posing to the occurrence of accidents. But these may be 

 prevented. Antianaphylaxis is the name given by Besredka to 

 the condition of insensibility to which the sensitive animal can 

 rapidly be brought. But though in current language one talks 



■* There exist other physiological shocks which are deadened by narcosis, 

 and it is impossible to avoid a comparison between the above experiment 

 and one of Jellinek's (the director of the laboratory of electrical pathology 

 in Vienna) reported in a recent lecture by D'Arsonval. 



' ' A rabbit is fairly easily killed when the opposite poles of an alternat- 

 ing current of 1,500 volts are placed in its mouth and rectum, whereas a 

 rabbit of the same breed but so deeply chloroformed that all its vital 

 phenomena have ceased is at once reawakened and saved from death by 

 the same current. 



" At the time that this experiment was published an English engineer, 

 Aspinall, observed that two electrical engineers who had during sleep come 

 into accidental contact with an alternating current of 3,000 volts were 

 simply awakened by burning sensations in the back without other injury." 

 (Jellinek). 



