PLEUEISY. 653 



In our patients the puncture can be made in the fifth or 

 sixth intercostal space, and as near to the anterior margin of the 

 rib as possible. It is usual to divide the skin with the lancet, 

 and to stretch it before introducing the trocar, so that, when the 

 fluid is withdrawn, the external wound is not directly opposed 

 to that in the tissues. By this method admission of air into 

 the cavity of the thorax is prevented. 



Physicians are agreed that it is not necessary to extract the 

 whole of the fluid, and that the removal of just so much as may 

 be necessary to relieve substantially the mechanical distress will, 

 in most cases, give the necessary spur to the natural process of 

 absorption, by means of which the rest of the fluid will be taken 

 up. Should the cannula become blocked up by fibrinous 

 coagula, and the escape of the fluid thus prevented, a whalebone 

 probe must be introduced. 



After the operation the animal's strength must be maintained 

 by good food and stunulating tonics, such as nux vomica, ferrous 

 sulphate in combination with hydro-muriatic acid. If the animal 

 does not feed, it should be supplied with milk and eggs instead 

 of its drinking water for a day or so ; but, for reasons already 

 given, all such food must be partaken by, not forced on, the 

 animal. 



