ESSAYS ON BACTERIOLOGY. 91 



Second, the long-debated question of the relation- 

 ship of diphtheria and membranous croup has been 

 approaching a solution upon a basis which appears to 

 be reliable. It does seem as though we shoul,d soon 

 have a definite and positive answer to this vexed ques- 

 tion. Extensive and accurate investigations have 

 clearly proven that a large proportion — about 80 per 

 cent. — of the cases ordinarily reported as membran- 

 ous croup are membranous laryngitis, due to the 

 poison of diphtheria. Acting, as they must, upon 

 this demonstration, health boards are now coming to 

 be almost unanimous in requiring a report of such 

 cases, and in dealing with them as diphtheria. The 

 presumption niust be that at least the great majority 

 of them are diphtheria. Clinical features, which 

 still seem to sustain the doctrine of duality, there may 

 be in some cases; but when from many of even such 

 cases the microbes of diphtheria are obtained and be- 

 ing cultivated and inoculated, show their infectious 

 quality, then, in the language of Virchow, as applied 

 to antitoxin, theories must give way to the brute force 

 of facts. Physicians, therefore, whatever their indi- 

 vidual views as to membranous croup, should recog- 

 nize the force of the facts, and should cheerfully sup- 

 port the health boards in foUowiag the course which 

 is evidently' the one of wisdom and safety. 



-At the same time it is to be said that, just as there 

 are now known to be cases of membranous pharyn- 

 gitis resembling diphtheria, but not due to the diph- 



