ACUTE INFECTIOUS DISEASES. 



the disease there may be high fever, but no change perceptible at 

 the point where the diphtheritis subsequently appears ; also that in 

 scarlatina, which is a primary blood-disease, diphtheria often occurs. 

 The claims for the local origin of the disease are supported by the 

 results of inoculation, which tend to show that the disease starts 

 from the point of inoculation and spreads through the body. It 

 has been asserted that these experiments prove nothing certainly, 

 and that inoculation of other decomposing substances may induce 

 the same changes as the diphtheritic membrane causes. If the diph- 

 theritic poison entered the lungs and was thence transferred to the 

 blood in some cases, and located and was propagated in the pharynx 

 in others, it would perhaps explain both classes of cases. Some 

 English observers consider it as established that milk is frequently 

 an infectious agent ; whether the poison is generated in the cow 

 itself, or whether the milk is merely a carrier of germs taken in 

 the cow's food, is not decided. 



Persons in the vicinity of a diphtheria patient may have a catar- 

 rhal angina due to the poison. A second form is croupous diph- 

 theritis, with a membrane which may be readily detached from the 

 subjacent mucous membrane. The third and severest form is where 

 the fibrinous deposit is both on and in the membrane ; between the 

 fibres are pus- and blood-cells, micrococci, etc. ; the mucous mem- 

 brane is quickly destroyed, leaving gray or brown sloughs, which 

 render the breath very foul ; this slough may extend to the sub- 

 jacent cartilage or bone. 



Deeper in the air-passages, diphtheria is croupous in nature ; 

 the ulceration of the mucous membrane does not usually extend 

 below the larynx, that is, where pavement changes to cylindrical 

 epithelium. In persons who have died of diphtheria, the blood is 

 generally imperfectly coagulated, dark, and tar-like. Changes in 

 the kidneys are very common. 



The latent stage of diphtheria is usually short, though cases 

 occur where it is possibly of some weeks' duration. The catarrhal 

 form has the same symptoms as ordinary angina, and it may be only 

 the surrounding circumstances that would lead us to suspect diph- 

 theria ; it may run its course in this way, or become a severe dis- 

 ease. Croupous diphtheria is usually accompanied by high fever ; 

 there may be burning in the throat or pain on swallowing ; if these 

 symptoms be absent, the disease may for some time escape recogni- 

 tion. Inspection shows the mucous membrane to be dark red and 

 swollen, with deposits of false membrane, which develop rapidly, 

 and may even cover the whole pharynx and extend into the nares 

 or middle ear, but especially into the larynx, or else may remain 

 confined to the pharynx. The latter cases are apt to terminate 



