84 OP RESPIRATION, 



SECT. VIII. 



OF RESPIRATION AND ITS PRINCIPAL, USE, 



134. THE lungs,* closely connected with the heart 

 both by proximity and by relation of function, are two 

 Viscera, large after birth, so light as to swim in water, 

 and composed of a spongy, and, as it were, spumous', 

 but pretty tenacious, parenchyma, f 



135. They fill each cavity of the chest, and are con- 

 tiguous to the sacs of the pleurae, to which, as well as 

 to the other contents of the thorax, they model and 

 apply themselves. (A) 



136. They, in a manner, hang from the wind-pipe 

 usually called the aspera arteria, which, besides its 

 interior coat always smeared with mucus, and the sub- 

 jacent very sensible nervous coat, consists of another 

 which is muscular, surrounding the latter, and divided, 

 except posteriorly, by an indefinite number of cartila- 

 ginous falciform arches. 



137. The aspera arteria, having entered the thorax, 

 is bifurcated into the two bronchia?, and these, the 

 more deeply they penetrate into the lobes and lobules 

 of the lungs, are the more and more ramified, losing 



* Soemmerring and Reisseiscn, iibcr die Structur, die Verrichtung und den 

 Gelrauclt der Luiigen. Zwey Preischriften. Berlin. 1808. 8vo. 



t Respecting all the organs concerned in respiration, consult Corn. J. Van 

 Der Boscli, Anntnmia Systemcttis Re.ipirationi inservientis Pathologica. 

 Harlem. 1801. -Ito. p. 144. 



