74 



DR CHARLES J. PATTEN. 



the formalin heart. But when the heart is lifted even partly 

 out of the pericardial sac it loses its proper form, owing to 

 the collapsing of the flaccid and often empty chamber of the 

 right ventricle. Hence it is necessary to harden the organ in 

 order to get a proper idea of the form of its inferior and 

 posterior aspects. 



The sivrfaces. — In hearts removed from the pericardial sac 

 and hardened with formalin, I could make out three distinct 

 surfaces. These are seen in Plate IV. figs. A. and B. They 



suS 



Configuration of the Formalin Heart mapped out on the chest wall. 



are separated from each other by more or less distinct borders. 

 The surfaces are as follows : — 



1, Anterior (facies sternalis), which looks forwards and down- 

 wards. It is separated from the hasal or inferior surface by the 

 margo acutus and margo obtusus, and from the posterior or 

 auricular surface by the margo obtusus and right or auricular 

 border. 



2. The inferior or ' hasal ' surface (facies diaphragmatica), 



