172 CONDITIONS REQUIRED FOR 



ready inlet to contagion, miasmata, and other 

 poisonous influences diffused through the air which 

 we breathe. 



From this general explanation of the structure and 

 uses of the lungs, it will be obvious, that several 

 conditions, which it is our interest specially to know 

 and observe, are essential to the healthy perform- 

 ance of the important function of respiration. FIRST 

 among these we may rank a healthy original form- 

 ation of the lungs. No fact in medicine is better 

 established than that which proves the hereditary 

 transmission from parents to children of a constitu- 

 tional liability to pulmonary disease, and especially 

 to consumption ; yet no condition is less attended 

 to in forming matrimonial engagements. The 

 children of scrofulous and consumptive parents are 

 generally precocious, and their minds being early 

 matured, they engage early in the business of life, 

 and often enter upon the married state before their 

 bodily frame has had time to consolidate. For a 

 few years every thing seems to go on prosperously, 

 and a numerous family gathers around them. All 

 at once, however, while still very young, their phys- 

 ical powers begin to give way, and they drop pre- 

 maturely into the grave, exhausted by consumption, 

 and leaving children behind them, destined in all 

 probability either to be cut off as they approach 

 maturity, or to run through the same delusive but 

 fatal career as that of the parents from whom they 

 derived their existence. 



Many examples of this kind might be pointed out 

 among the higher classes of society, who are not 

 restrained from following their predominant incli- 

 nations, by any necessity of seeking subsistence in 

 professional pursuits. And many instances might 

 be referred to, in which no regard was shown to the 

 manifest existence of the same disposition in the 

 family of either parent, and in which, consequently, 

 the marriage state was imbittered either by barren- 



