EMPHYSEMA OP THE LUNGS. 73 



coction of senega ; wine ; and to feed the patient well on milk or 

 beef tea."* 



The regimen should be strictly antiphlogistic ; and with a view to 

 prevent vomiting," very little liquid should be allowed during the an- 

 timonial treatment. During convalescence from this and all other 

 acute diseases of the chest, visiters should be excluded, as talking, 

 even in an under tone, is injurious to the patient. 



EMPHYSEMA. OF THE LUNGS. 



The term emphysema of the lung, given to this disease by Laennec, 

 is not strictly applicable, inasmuch as that term signifies an escape 

 of air into the cellular tissue. This disease, more correctly speaking, 

 consists in a dilatation of the air cells ; the parieties of which may 

 also be ruptured, in which case several may coalesce, and form a 

 cavity of some extent. 



Causes. — It has been stated that long-continued and violent 

 coughing acts in distending the air-cells beyond their ordinary 

 dimensions, and from this repeated dilatation they finally become 

 permanently enlarged. Again, in cases of chronic catarrh, particu- 

 larly of the dry kind, the small bronchial ramifications become so 

 obstructed by the swelling of their membrane, or by the secretion 

 of a viscid mucus, that the air can only be forced through them into 

 the vesicles by a considerable effort. Now, an inspiration is more 

 forcible than expiration ; the former may be sufficient to overcome 

 the obstacle to the admission of air into the vesicles, while the latter 

 is not adequate to its expulsion : thus the vesicles would be kept in 

 a permanently distended state. Further, an additional cause has 

 been suggested by I^aennec, namely, the expansion of the air in 

 consequence of the temperature of the body. Successive portions 

 of air expanding by the increased temperature, are thus introduced 

 and incarcerated in the cells, which are thereby kept in a continual 

 state of dilatation. Dr. Williams observes — " In dry chronic catarrh, 

 the general starting point of emphysema, small particles of viscid 

 mucus form a kind of movable obstruction, which, falling into a 

 bronchial ramification, instantaneously and eflfectually plug up the 

 tube. Now, suppose this to happen in a tube at the termination of 

 an expiration ; inspiration takes place, but this pellet of mucus acts 

 as a valve, preventing the entry of air into the cells, supplied by 

 this tube ; the consequence is, that the air in the surrounding cells 

 presses in to fill the vacuum, by dilating or rupturing their mem- 

 branous tunics." Miliary tubercles, and other causes, producing par- 

 tial pressure and obstruction among the air-cells, may lead to the 

 development of this disease. To the practical physician, however, 

 the great point of consideration is, that this aflfection is the result of 



* Dr. Watson's Lectures, vol. ii., p. 93. 

 7 



