420 Mr. J. F. Bullar. Experiments to Determine the [Nov. 27, 



in the chest in health and in consolidation of the lung are represented 

 accurately enough for the purpose, and that they illustrate the way 

 in which bronchial breathing may be produced in extensive consolida- 

 tion, and in any other conditions which give rise to a stasis of air 

 in the bronchial tubes. 



Fio. 6. 



In such cases a new sound is produced at the junction of the obstructed 

 with the unobstructed tubes. This sound does not exist in health. 



If the respiratory organs themselves and the structures covering 

 them were good conductors of sound, the sounds produced at any part 

 would be heard at all other parts, and wherever we listened on the 

 surface of the chest or throat, we should hear the combination of all 

 the sounds produced at the time in the different parts. For the dis- 

 tance between the most remote parts of the respiratory tract is so 

 small that none but very feeble sounds would be entirely lost on that 

 account, even if it were not the case that in a great part of this short 

 distance the sound is conducted through tubes (trachea and larger 

 bronchi), by which the effect of distance is diminished. 



Of course each sound would bear a somewhat greater or less pro- 

 portion to the whole combination, as the point ausculted was nearer 

 to or farther from the seat of its production, and thus there would be 

 a difference of character in the resultant or combination sound at 

 different parts ; it would, however, at all parts be a combination of 

 the sounds produced in the different parts of the tract. The rate of 

 the air-currents is so slow as to have no influence on the conduction 

 of sound. 



The bronchial breathing produced in the artificial system of tubes 

 was heard equally well in all the tubes. In the body, however, this 

 is not the case, the bronchial breathing heard over a consolidated 

 lung is not recognised on the healthy side, owing to the feeble con- 



