550 
W. E. A. WYMAN. 
the duration of the disease producing the reflex act. Of course 
I do not wish to convey the idea that cough will lead to a posi¬ 
tive diagnosis as to the seat of the trouble in every instance. 
Nevertheless, the artificially produced cough or the spontaneous 
cough is often diagnostic to the experienced ear and ma}^ under 
certain conditions be a decisive factor. I need only remind of 
the short, weak, painful and evasive cough of an acute pleurisy. 
Friedberger and Frohner say that a definite disease cannot be 
diagnosed by the quality of the cough only. The trained ear of 
the American practitioner at the same time quickly recognizes 
by the character of the cough a laryngitis, pneumonia or pleurisy 
or even a bronchitis not to be detected by auscultation. There¬ 
fore, the diagnostic importance of cough cannot be overesti¬ 
mated. 
Cough indicates a diseased state of some portion of the res¬ 
piratory tract; its quality being distinctly shaped as to the seat 
of the irritative process. Consequent!}^ both artificial and spon¬ 
taneous coughs are fundamental guides in the diagnosis of dis¬ 
eases of the respiratory apparatus. When an animal is coughed 
by slight pressure upon the trachea or larynx, it is apparent 
that the part or parts compressed are hyperasthetic, while the 
nature of the cough thus induced reveals the region if not the 
seat and often the stage and intensity of the morbid process. 
When spontaneous cough is present and slight pressure upon 
the larynx or trachea yields negative results, it is reasonable to 
presume that the source of the cough lies below the point com- 
* pressed during the examination. At the same time cough result¬ 
ing from compression of the larynx or trachea as practiced to 
produce artificial cough does not necessarily indicate exclusive 
disease of the laryngeal or tracheal mucous membranes, as the 
mucous membranes of the bronchi may also be involved. In 
such a case the nature of the cough would be a valuable guide. 
Lymphatic animals and those with a short neck are often diffi¬ 
cult to cough. 
In acute and chronic diseases of the mucosae of the respira¬ 
tory tract of a superficial type are always accompanied with 
