BOVINE DIPHTHERIA. 
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stated by Bretonneau in 1821 to 1826, who applied to it the term 
diphthetrite, whence originated the name diphtheria, proposed by 
Trousseau. This name, the significance of which relates to the 
most characteristic local event, namely, the formation of a false 
membrane, has the negative merit of not involving any hypoth¬ 
esis concerning the pathology of the affection. 
Diphtheria is defined as a specific infectious disease char¬ 
acterized by a local fibrinous exudate, usually upon a mucous 
membrane, and by constitutional symptoms of varying intensity. 
The presence of the Klebs-Loffler bacillus may be regarded as 
the etiological criterion by which true diphtheria may be dis¬ 
tinguished from other forms of pseudo membranous inflamma¬ 
tions. 
Etiology .—Diphtheria is endemic in the larger cities of pop¬ 
ulation, and at times epidemic. It is a fact that while other 
contagious diseases have diminished within the past decade, 
this malady has increased in cities. This disease is not con¬ 
fined to cities ; it has prevailed in country districts, and the 
affection in many instances seems to be specially virulent. 
Sporadic cases occur under circumstances which seem to 
render it impossible that the special germ of diphtheria had 
been introduced from without, but a similar apparently sponta¬ 
neous development of other contagious diseases occurs, so that 
these instances cannot overthrow the general belief in the con¬ 
tagiousness of diphtheria. At times it is true that it is often 
impossible to trace the source of infection in cases of diphtheria. 
“ The experimental inoculations of animals with diphtheretic 
exudation has not yielded decisive results.” (Flint.) 
There is evidence of the transporting of the virus by indi¬ 
viduals who do not become infected with the disease. The 
contagion of diphtheria often adheres tenaciously to localities 
where it has once gained a foothold, and months may elapse 
and then a case occurs. Surroundings and conditions do not 
appear to be connected with the causation. It occurs at all 
seasons of the year, but most frequently during the changeable 
weather. The period of incubation is generally between two 
