K-QP6 



EDITOR'S PREFACE. 



ALTHOUGH Hewson's merit, as a physiologist, is generally 

 admitted, his writings have been unjustly neglected, and are 

 now so scarce that a complete copy of them is not to be found 

 in the stock of any London bookseller, nor even in some of 

 our best libraries, as that of the British Museum. 



Hence a new edition of Mr. Hewson's Works will be both 

 an acceptable present to physiological literature and a just 

 tribute of respect to his memory. 



His Plates, which have all been carefully engraved on this 

 occasion, will always be interesting. It is true that some of 

 them might now be displaced by others containing more exact 

 information in the same space ; but then historical truth would 

 suffer, and the conscientious inquirer would still be compelled 

 to consult the old copies. 



In the Introduction^ an account is given of Hewson's life 

 and writings, with a careful survey of the facts ascertained 

 and opinions held concerning the blood by his predecessors 

 and contemporaries, followed by an estimate of the value of 

 his Inquiries. This course appeared necessary in justice to 

 the old physiologists, and well calculated to afford an interest- 

 ing and instructive view of the progress of research in a most 

 important subject, about the history of which so much error 

 prevails. 



An attempt has been made to place the matters to which 

 the Notes relate on a level with the present state of know- 

 ledge ; while in them also the historical method has generally 



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