PHILOSOPHICAL SOCIEffY OF WASHINGTON. 125 



cartilaginous tissue. These changes are commonly most marked 

 in the left lung. 



On examination, as before directed, we find that animals whose 

 normal respiratory system more or less resembles, in structure 

 and function, the respiratory apparatus of the consumptive 

 patient, are to be found among the different tribes of serpents, 

 frogs, toads, tortoises, turtles, etc. The natural environments of 

 these animals were such a^to demand of their respiratory organs 

 only a limited amount of function as compared with those of 

 man ; hence it was inferred that partially similar environments 

 must have impressed the human individual in whom the chronic 

 changes of sM-ucture, just noticed, were developed, and which he 

 therefore designated Fihrotic Atrophy of the Eesinratory Appa- 

 ratus. 



The conclusion thus reached he considered was sustained by- 

 actual observation in practice. Thus muscular indolence, espe- 

 cially such as is inseparable from a sedentary life and indoor 

 occupations or confinement in prisons; and prolonged silence or 

 vocal indolence, together with persistent mental depression, were 

 universally acknowled first causes of phthisis ; in all of them the 

 demand for respiratory function was reduced, and the consequent 

 modification of the respiratory organs was a conservative attempt 

 to adapt the individual to his unnatural surroundings. Opposite 

 environments, viz., such as necessitated active locomotive exer- 

 cise, vocal exercise, and promoted hilarity and mental exhilara- 

 tion, were admitted prophylactics of consumption. Hence ora- 

 tors, pedestrians, and pugilists (the latter, however, only prior 

 to their "retirement from the ring") were comparatively exempt 

 from the disease. 



Active respiratory function also promoted activity of the por- 

 tal circulation, and consequently a good digestion, hence the 

 theory that the disease was due to imperfect assimilation of food 

 (a theory ably supported by Sir James Clark, Dr. Wilson Philip, 

 Prof. J. H. Bennett, and others) was admitted only with the 

 proviso that the impaired assimilation arose from impaired por- 

 tal circulation consequent upon the restriction of the motions of 

 the diaphragm and abdominal walls that were inseparable from 

 a restriction of the respiration. 



The fibrotic atrophy of the respiratory system was conser- 

 vative, considering the environments under the impression of 

 which it arose, in protecting the individual from fatal hyper- 

 oxidation of the blood — a condition actually existing during the 

 first stage of phthisis, as proved by the arguments and experi- 

 ments of Beddoes, Liebig, Ancell, Simon, Rokitansky, and others. 

 Mr. King concluded his paper with the remark that the views 

 he liad presented were in conformity with the principles of Dar- 

 winian evolution. Man had attained his present nobility of 

 development by successive and gradual increments of functional 



