132 TOXINES AND ANTITOXINES. 



The unit of measurement chosen was a solution of the poison, 

 O01 c.c. of which killed a guinea-pig of 200 to 300 grms. on 

 subcutaneous injection. In the case of rabbits death did not 

 take place until after the lapse of an hour after the intravenous 

 injection of even 1,000 lethal doses ; the lethal dose for them on 

 subcutaneous injection was O'l to 0-2 c.c. of the normal poison. 

 Similar amounts per kilo, of body weight were also fatal to 

 monkeys, dogs, hedgehogs, mice, hens, pigeons, sheep, and oxen. 

 The lethal dose for a young ox was 40 c.c. of the normal poison, 

 while sheep required about 2 c.c. Frogs were refractory, but 

 retained the poison within their body. 



The poison passes very slowly through a porcelain filter and 

 is hardly dialysable. It resists freezing and thawing, and light 

 has but little injurious effect upon it, but it is affected when 

 heated even to 30 C. On the other hand, it can be dried in a 

 vacuum in the cold. It is almost completely destroyed in an 

 hour when exposed to a temperature of 50 C., so that very large 

 doses (7 to 10 c.c.) then produce only local swelling. It becomes 

 rapidly weaker even when kept in an air-tight vessel and still 

 more rapidly when exposed to the air. 



It is destroyed by permanganate added in the proportion of 

 0*15 per cent., by phenol (1 per cent.), and formaldehyde (0-1 per 

 cent.), while "salting out" with ammonium sulphate and pre- 

 cipitation with alcohol and ether have a considerable injurious 

 effect. Chloroform is absolutely without influence upon it. 



The poison of symptomatic anthrax is also shown to be a true 

 toxine by the fact that it is possible to produce an antitoxine to 

 it. Guinea-pigs cannot be used for this purpose since they are 

 too susceptible, but it can readily be done with rabbits and oxen. 

 It is very easy to immunise the latter, and they yield sera of 

 high antitoxic value (up to 400-fold), whereas even highly 

 immune rabbits give sera which are only weak in antitoxine. 

 The ratios between the toxine and antitoxine show numerical 

 proportions exactly analogous to those observed, e.g., in the case 

 of diphtheria toxine (marked variations in the value of D, 

 swellings caused by the injection of mixtures in the "differential 

 zone," &c.), and thus point to the presence of toxones. On the 

 other hand, there does not appear to be any formation of toxoids, 

 since the decrease in the toxicity keeps parallel with the decrease 

 in the combining power. Moreover, combination appears to 

 take place very slowly. 



The antitoxine appears to be very stable (it can be kept for 

 two years). It is not dialysable ; it can be dried and can resist 

 a temperature of 60 to 65 C. for an hour. 



