1896.] rapidly producing Diphtheria Antitoxines. 



295 



toxine. During the first twelve days this horse received 380 c.c. of 

 serum toxine (see Table I) spread over three injections on different 

 dates. On the nineteenth day of the experiment it received 50 c.c. of 

 unfiltered serum toxine (sterilised at 65° C.) and 150 c.c. of broth toxine, 

 of which one half c.c. killed a 500 gramme guinea-pig in forty-eight 

 hours. The unfiltered serum toxine unfortunately gave rise to a small 

 abscess which greatly impeded the treatment, and subsequent experi- 

 ence has convinced me that the bodies of the bacilli which gave rise 

 to this irritation must be removed by filtration if the process is to be 

 carried out smoothly and successful^. On the 28th day it received 

 50 c.c. of the same broth toxine, and on the 30th day another injection 

 of 115 c.c. 



The horse was then bled on the thirty-second day of treatment, and 

 the serum was found to possess the strength of ten normal units, 

 that is to say, l/100th of a c.c. protected a 250 gramme guinea-pig 

 against ten lethal doses of broth toxine. As this strength is only 

 attained by Iloux's method after at least ten weeks' treatment, it was 

 evident that the serum toxine had considerably shortened the process. 

 It may be mentioned that the horse, which had been in very poor 

 condition at the beginning of the treatment, steadily improved 

 during the month. The experiment was not carried further with 

 this horse, which was then subjected to the ordinary method for 

 producing antitoxines, when it reacted in every respect like an 

 animal which had been under the usual treatment for several 

 months. 



In the case of the next horse (No. 2) it seemed safe to inject much 

 larger quantities of the serum toxine, but to avoid the risk of con- 

 stitutionally injuring the animal the addition of a certain amount of 

 antitoxine was made. During the first twelve days (Table II) 1350 c.c. of 

 serum toxine had been injected and mixed with this 50 c.c. of antitoxine 

 obtained from the previous horse, each c.c. of which contained ten 

 normal units. During the next week 550 c.c. of broth toxine (of which 

 1/4 c.c. killed a 500 gramme guinea-pig in forty- eight hours) was 

 injected, spread over three injections, and to the last of these 100 c.c. 

 of serum toxine was added. In the succeeding week it received 

 400 c.c. of the same broth toxine mixed with 250 c.c. of serum toxine 

 in two injections. On the thirtieth day the animal was bled (3/4 of a 

 litre) and the antitoxic value of its serum estimated. It was found 

 that 1/100, 1/200, 1/300, 1/400, 1/500, and finally ] /1000th of a c.c. pro- 

 tected completely against ten lethal doses of the toxine. After six 

 weeks of treatment l/1600th of a c.c. protected against ten lethal 

 doses, while on the ninth week l/2500th of a c.c. sufficed. 



In this experiment, which furnished such brilliant results, as has 

 been stated antitoxine was mixed with the serum toxine injected, but 

 that this was not at all necessary was shown by a subsequent experi- 



