EFFECTS OF TIGHT LACING. 305 



976. It is shown by Fig. 96, and its description, that 

 the lungs are always in contact with the diaphragm, and 

 that they completely fill the cavity of the chest on each 

 side of the heart ; this cavity cannot therefore be dimin- 

 ished, without exerting a direct pressure on the organs of 

 respiration. 



977. It is further shown, p. 152, that the lungs are 

 composed of a tissue of blood and air vessels, of such ex- 

 treme tenuity, that the latter have been computed to 

 amount to nearly two hundred millions in number, forming 

 a surface of many hundred feet in extent ; and that the 

 blood-vessels are equally numerous, presenting a surface 

 similarly extensive. And however incredible it may ap- 

 pear, the whole extent of these two surfaces, thus present- 

 ed to each other, and by means of which, a vital process 

 is effected, without which we could not live a moment, is 

 still contained within the narrow spaces occupied by the 

 lungs ; each of which do not exceed a foot in one direc- 

 tion, and six or eight inches in the other. 



978. Now who believes, that organs so " wonderfully 

 and fearfully made," so frail and delicate in their struc- 

 ture, as to present tissues of circulating vessels scarcely 

 exceeding a spider's web in size, will permit such an 

 abuse, as to be compressed into one third, or even one 

 half their natural dimensions, without some punitive inflic- 

 tion on those who have the temerity to offer such violence 

 to nature. 



979. The first effect produced by compressing the lungs, 

 will be a want of due oxygenation of the blood ; because 

 many of these minute vessels must thereby be closed 

 against the admission both of the air and the circulating* 

 fluid. 



980. By a reference to the article " Circulation," p. 130, 

 it may be seen that in the amphibia, only one half of the 

 blood circulates through the lungs ; and that in the fishes, 

 there is no aorta by which it is carried to the different 

 parts of the system as in other animals. The quantity 

 of blood in the latter is also exceedingly small, when 

 compared with that of other animals of the same size. 

 In the amphibious animals, therefore, the circulating fluid 

 consists of one half arterial, and the other half venous 

 blood ; and on this account, these tribes are cold-blooded, 



26* 



