418 PATHOGENIC BACTERIA. 



546 cases in which the antitoxin was first injected after 

 the third day of the disease yielded a fatality of 27.8 per 

 cent. 



After the toxin has set up destructive organic lesions 

 in various organs and tissues of the body, no amount 

 of neutralization will restore the integrity of the parts, 

 so that the antitoxin must fail in these cases. 



The urticaria which sometimes follows the injection 

 of antitoxic serum seems to depend upon the globulins it 

 contains. 



I have found that the "keeping" qualities of the se- 

 rums, when properly preserved, are of long duration. 

 Samples examined two years after having been exposed 

 for sale in the markets have been found unchanged. 

 The serums most prone to deteriorate seem to be those 

 of highest potency, but even here the good qualities are 

 unchanged for months. Serums, however, are by no 

 means regular in their deterioration, and no very old 

 serum should be used for the treatment of diphtheria. 



Freezing is without effect and ordinary temperature- 

 changes are harmless to the serum. The antitoxic power 

 is destroyed at 6o° C, the point at which the serum 

 coagulates. The antitoxin is precipitated with the glob- 

 ulins. 1 



The erythemata are probably in some way associated 

 with the globulocidal action of the blood. The serums 

 from different horses probably vary much in both their 

 irritant and globulocidal properties, so that antitoxins 

 prepared by mixing the serums from a number of horses 

 are probably preferable to those from single horses. 



The transitory nature of the immunity afforded by 

 prophylactic injections of the antitoxin is probably de- 

 pendent upon the fact that the antitoxin is slowly ex- 

 creted through the kidneys. 



Bacilli Resembling the Diphtheria Bacillus. — The 

 Pseudodiphtheria bacillus — Bacillus pseudodiphthericus — 



1 See paper by J. P. Atkinson, Journal of Experimental Medicine, Sept. 

 .and Nov., 1899, vol. iv., Nos. 5 and 6. 



