RESPIRATION. 123 



by the parts in the mouth, &c., so as to produce articulate speech. 

 Singing-birds have a simple larynx at the top, and a complicated 

 me at the bottom of the windpipe. 



f DISEASES. 



When foreign bodies, such .as cherry or plum stones, get into the 

 larynx or windpipe, they cause excessive irritation, and not unfre- 

 quently death. A few years ago, a child swallowed a clasp, one 

 half entered the windpipe, the other the gullet. When I attended 

 the medical lectures in the old Barclay street Medical University, 

 this specimen, preserved in spirits, was exhibited to our class. The 

 professor staled that the foreign body might have easily been re- 

 moved had any one present possessed a little anatomical know- 

 ledge. 



Affections of the top of the windpipe produces suffocation, and, 

 among these, by far the most common and fatal, is croup. This 

 disearse consists in inflammation and swelling of the inner or mu- 

 cous lining of the larynx and windpipe. 



When the inner or mucous membrane of a few of the larger 

 knches of the windpipe is slightly inflamed, it is called a common 

 cold ; when the inflammation is greater and extends to the lesser 

 air-tubes (bronchi), it is called bronchitis, and is often denoted by 

 considerable wheezing in the breathing;* when the air- vesicles, 

 and the substance which connects them, become inflamed, it is 

 called inflammation of the lungs (pneumonia). The last is a very 

 fatal disease, if not early checked. The importance of early atten- 

 tion to it will be understood from this, that it consists of three 

 stages, in the first of which the part of the lungs affected is merely 

 engorged with the watery serum of the blood. A free perspiration 

 will frequently remove this,. But if allowed to remain, this rapidly 

 passes into the second stage, in which the lung becomes solid, like 

 a piece of liver (hepatization\ and ultimately into the third stage, 

 when the solid portion is infiltrated with matter (pus). The two 

 latter stages are comparatively seldom recovered from. 



When the membrane (pleura) covering the lungs and lining the 



* Millers, masons, sawyers, grinders, and others who are exposed to the inhalations 

 of various kinds of dust, are very subject to this disease, and have their lives much 

 shortened by it. Dry grinders seldom live beyond 30 or 35 years. In M. Lombard's 

 returns for Geneva, the average longevity of stone-cutters is stated at 34 years, of sculp- 

 tors at 36 years, and of millers at 42 years ; while painters live, on an average, to 44, 

 joiners to 49, butchers 53, writers to 51, surgeons to 54, masons to 55, gardeners to 60, 

 merchants to 62, preachers to 63, and magistrates to 69 years. 



