424 DISEASES OF THE RESPIRATORY ORGANS. 



local and general, and in addition by certain physical signs 

 indicative o: aberration of healthy fvniction and structural 

 change. These physical signs being individually and collec- 

 tively much relied upon, it Avill be needful, before proceeding 

 to consider in detail the diseases to which this class of organs 

 is subject, to give them a short review. 



Methods and Objects of Physical Examination. 



The different physical modes of examination by which an 

 endeavoiu' is made to estimate either the liealthy or diseased 

 condition of the thorax and its contained organs are — 1. Inspec- 

 tion of the for in of the thorax ; 2. Mensuration; 3. Palpation; 

 4. Percussion; 5. Auscultation; 6. Succussion. 



These several means of obtaining information relative to the 

 condition of the chest and the organs contained therein, or of 

 confirming opinions formed in the observation of vital symp- 

 toms and general states of the constitution, apart from which, 

 even when most carefully noted, they will ever be fruitful 

 sources of error, are not equally applicable to every disease of 

 those organs. Being, however, of such general application in 

 our day, it behoves us to understand how much Ave may 

 expect to receive from these, and the best means by which 

 these methods may be cultivated. 



Of none of these means of strengthening our diagnosis of 

 thoracic disease — particularly the two most frequently em- 

 ployed, auscultation and j)('i'ciission — can we obtain a com- 

 petent knowledge by reading, however carefully, any description 

 of them ; far less can they be mastered so as to give us reason- 

 able grounds for resting on them for support. They must be 

 assiduously and carefully wrought out by ourselves by actual 

 employment on the living animal. The condition of the chest 

 and of the contained organs in healthy animals ought, first of 

 all, to be our study, so as to familiariice our ear and eye with 

 the normal sounds, condition, and appearance; when suffi- 

 ciently acquainted with these, diseased conditions may be 

 attempted, ever in any doubt having recourse to the examina- 

 tion of the healthy. 



With this, as with every separate method of investigation 

 and means of obtaining knowledge of the phenomena of 



