

RESPIRATION. 129 



as the metal melts at the boiling point of water, it finds its way 

 into the most minute ramifications. When heated, the air in the 

 air-tubes causes the lungs to become buoyant, which prevents the 

 metal getting properly into the lower bronchi. To obviate this, 

 the lungs may be enveloped in a cloth, which should be loaded with 

 heavy weights, to keep them in the upright position. As the metal 

 is extremely brittle when hot, the lungs should not be taken out of 

 the pot till they are cold ; then hang them in some place where 

 flies can deposit their eggs, moistening the outside daily, and allow 

 them to remain until the maggots eat away all the flesh ; after this, 

 hang them in water until the preparation can be easily cleaned. 

 In making both preparations, about one and a half pounds of metal 

 vtt required, and the tin filler should be heated to make the metal 

 run the easier. If any of the large branches are broken, any tin- 

 smith will easily solder them. When well managed, preparations 

 made in this way have a truly wonderful appearance ; the 

 bronchial tubes, though beautifully distinct, and as fine as hairs, 

 presenting almost a solid mass. The existence of air-vesicles has 

 Jieen doubted by some authors, and these preparations seem to sup- 

 port this opinion. 



BDther illustrative figures for this section will be found in Bell's 

 Anatomy, vol. i., page 699 ; Dr. Smith's Philosophy of Health, 

 vol. i., p. 243 ; " Animal Physiology," in the Library of Useful 

 Knowlege, pp. 88, 89, 92, &c., &c. 



MEDICAL TREATMENT AND REGIMEN. 



aving given a description of the structure, physiology, and 

 iseases of the lungs, I will add a few remarks on the medical 

 treatment and regimen of pulmonary disease, being the most com- 

 mon complaints of these organs. It is a melancholy fact, that 

 diseases of the lungs cause greater mortality than all others to- 

 gether, particularly in all northern climates. In this country and 

 in England, about one-fourth or fifth adult persons are taken off by 

 consumption, the causes of which are various, principally sudden 

 changes of the weather, which is exceedingly great, even not un- 

 frequently during a single day. This checks the secretion of the 

 skin, and retains deleterious agents, which become a source of irri- 

 tation ; and in addition to which that immense amount of blood 

 which is constantly distributed to every part of the body, particu- 

 larly the surface or skin, is forced inwardly by the refrigeratory 

 influence of cold, and closes the capillary vessels, and drives the 

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