PREFACE. 



THE knowledge of the human frame, the preservation of 

 health, and the cure of diseases, are objects of too great im- 

 portance to mankind for the author of these sheets to doubt 

 that any attempts to promote them, how small soever, should 

 not meet with a candid and indulgent reception from the 

 public. An Inquiry into the Properties of the Blood, it is 

 presumed, will be thought, in a particular manner, interesting, 

 since there is no part of the human body upon which more 

 physiological reasoning is founded, nor any from which more 

 inferences are drawn for the cure of diseases. And, as the 

 Inquiry is made by Experiments upon the Blood as near as 

 possible to the state in which it circulates in the vessels, it is 

 hoped that the conclusions made from them will stand the 

 test of a candid examination, and lead to further observations 

 and improvements. 



Since the publication of the first edition, some new Experi- 

 ments have been made, and a new chapter has been added, 

 which contains a recapitulation of the principal facts and con- 



