158 DIPHTHERIA AND PSEUDODIPHTHERIA. 



When used as a preventative in persons exposed to the 

 danger of contagion with this disease, it gives protection for 

 several weeks. 



Dose of Antitoxic Serum. As a prophylactic from 200 to 

 500 units should be used, according to the age. For the 

 purpose of treatment not less than 2000 to 3000 units should 

 be injected at one time, and that as early as possible in the 

 course of the disease ; and this dose should be repeated in 

 twenty-four hours unless^lecided beneficial effects are noticed. 



The experience of the author, based on the examination 

 of several thousand cases of diphtheria treated by serum in 

 New Orleans, has shown that, with the exception of an occa- 

 sional urticarial rash, no untoward effect follows this treat- 

 ment. The explanation of this eruption has not been given, 

 but it is very probably due to some other elements contained 

 in the blood-serum of the horse, and appears to be much 

 more common following the use of serum taken from some 

 horses than from that of others ; it appears to have no rela- 

 tion to the antitoxic power of the serum. 



Bacillus Xerosis. 



Kutschert and Neisser in 1884 described a bacillus morpho- 

 logically identical with B. diphtheria. It is found occasionally 

 in the normal eye and constantly in the chronic conjunctivitis 

 known as xerosis. In its growth and staining properties it is 

 almost identical with the diphtheria bacillus. It can be differ- 

 entiated from B. diphtherise by growing on media containing 

 saccharose. The latter is acidified by B. xerosis and not by 

 B. diphtherise. With dextrin the reverse is true. 



QUESTIONS. 



I 



When and by whom was the Bacillus diphtherise discovered ? 

 How does it answer the postulates of Koch with regard to pathogenic 

 bacteria ? 



Where is the Bacillus diphtherise found ? 



Describe the appearance of the Klebs-Loeffler bacillus. 



Describe the staining of this bacteria. 



What characterizes cultures of the diphtheria bacillus? 



