Microbic Diseases Individually Considered. 295 



Diphtheria. 



In its widest meaning this term is applied to a 

 special form of inflammation of the integuments in 

 which a concrete exudate is produced in the thick- 

 ness of the derm and involves its mortification ; this 

 exudate is called diphtheritic. "When the fibrinous 

 deposit is limited to the epithelium the inflammation 

 is said to be croupous. These two forms of inflamma- 

 tion can be produced by very varied causes : these 

 are mechanical (compression), or physical (burns), or 

 chemical (caustics), or, finally, biological (parasites 

 and microbes). Among the number of parasites may 

 be mentioned the gregarinse of the contagious epi- 

 thelioma of poultry and the coccidia of typhlitis of 

 the same animals; among microbes a large number 

 possess the same faculty ; of these we need only re- 

 call the diphtheritic exudates of pneumo-enteritis of 

 the pig, of acute glanders, and of petechial typhus, 

 etc. Diphtheria of wounds, or hospital gangrene, 

 characterized by a superficial necrosis of the divided 

 tissues, must also be attributed to the contamination 

 of the latter by micro-organisms. 



From a clinical point of view the term diphtheria re- 

 fers to a specific disease due to a special germ, and 

 manifesting itself by an inflammation, with croupous 

 or diphtheritic evolution, of the respiratory and some- 



by protecting the parts of the nervous system not yet attacked by 

 the tetanus poison. (Tizzoni, Cattani: Id. XV, 17.) 



Tests of the curative action of the serum of immunized animals 

 made by Nocord, in the case of two sheep artificially infected 

 with tetanus, resulted unfavorably. (Ref. Jour. Comp. Path. VII, 

 l.)-D.] 



