132 



pressure P depending on this velocity and on the rate of ex- 

 pansion J. 



" It may be remarked, in conclusion, that for the com- 

 pleteness of the theory, and to show the connexion between 

 ail the variables of the problem, we should add equation (1) 

 to the two given by the Comte de Pambour, and thus, be- 

 tween the four quantities, v, R, P', P, we will have, in the 

 general case, the three following equations, leaving one of 

 those quantities indeterminate. 



l l+c, I + c 71 + gR , . 



t + c S , , 



va — ^— = ^ (b) 



'' a^ \qw ^ n^ qP J ^ ' 



Professor Harrison made the following remarks on the 

 Larynx, Trachea, and CEsophagus of the Elephant : 



" My principal object in the present communication is to 

 direct attention to a particular muscle in the elephant, con- 

 necting the back of the trachea to the fore part of the oesopha- 

 gus, and to which I would give the name of ' trachea-oesopha- 

 geal muscle.' As I do not find any mention of this in Camper's 

 works, or in the Encyclopedie Metliodique, or in the article 

 ' Pacchydermata,' by R. Jones, in Todd's Cyclopedia of Ana- 

 tomy, 1 conclude it has not been observed by former anatomists. 



" My attention was accidentally directed to it in the course 

 of the dissection of the thoracic viscera. When removing the 

 lungs and heart, I remarked an unusually close connexion to 

 exist between the trachea and oesophagus, and which, on ex- 

 amination, 1 found depended on a short, thick muscle, which ex- 

 tended from the back part of the bifurcation of the trachea to 

 the fore part of the oesophagus, and along which the fibres 



