INTRODUCTORY REMARKS. IX 



a key to many of the morbid actions which have 

 hitherto remained inexplicable. Why the study of 

 the phenomena of the circulation, of the laws regu- 

 lating it in health and disease, and of the con- 

 trivances by which its various effects are produced, 

 has hitherto remained an almost untrodden field, is 

 a question which I shall not now stop to discuss, 

 and I allude to it only as an excuse for my own 

 deficiencies. 



It would have been more consonant to my own 

 original intention, and perhaps have met with more 

 general approval, had the matter contained in the 

 following pages been systematically arranged. But 

 as the preparation of a treatise at all worthy of the 

 subject, one giving even an outline of the Physiology 

 and Pathology of the Circulation of the Blood, 

 would have involved the devotion of more time and 

 thought than I can spare from the active duties of 

 life ; and as there are still some very important points 

 connected with the views now submitted on which I 

 believe it possible to throw much additional light, I 

 am induced to be content at present with collecting 

 a few papers from different periodicals and adding to 

 them one or two more recent essays on the same 

 subject. 



I have altered nothing in the papers now re- 



