ROARING. 41 



whistled. In both 'states the sounds emitted were found 

 loudest in inspiration. At last^ I drew the ligature as 

 tight as I was able to do. In a minute afterwards, the 

 animal, after staggering a good deal, fell down, struggled 

 violently, and, suddenly throwing himself upon his side, ex- 

 pired in two minutes after he had fallen. I found the 

 membrane lining the windpipe reddened, and covered with 

 frothy mucus. The ligature had not completely obliterated 

 the canal : I could still pass a crow-quill through the con- 

 stricted part of it. 



From this experiment we learn — that a certain diminution 

 of the caliber of the air-tube produces roaring ; that fur- 

 ther diminution or contraction of its area causes whistling; 

 and that a degree of constriction beyond this occasions 

 signs of suffocation, which, if not relieved, end in the 

 extinction of vitality. A whistler, therefore, I should call 

 an intense roarer ; a wheezer, I should say, is something 

 short of an actual roarer. Be it remembered, however, that, 

 although we are attempting such nominal distinctions, in a 

 pathological view they must all come under one general 

 heading, which, by common consent, at present, we denote 

 by the appellation of " roaring." 



What is the cause of the sound ? The experiment 

 just detailed shows, as far as it goes, that the roaring is to 

 be ascribed to diminished area of the passage for the air 

 to and from the lungs ; and, in truth, this will be found to 

 be the essence of the etiology of roaring. We appear to 

 know little or nothing about roaring being liable to result 

 from other altered condition — say, an unusually diy one from 

 want of secretion, or from ulceration in the passage ; 

 though, to say the least about them, there seems to be room 

 for supposing these to be causes. Deprivation of elasticity 

 or pliability — as where parts become ossified — likewise have 

 the effect of occasioning roaring. The various collected 

 reports that have been made from time to time on the states 

 of the air-passages of roarers, have shown that all of them 

 have produced the effect in one of three ways, viz. either by 

 contraction of the passage or its orifice ; by distortion or 



