i v TRANSLATORS' PREFACE TO THE EDITION OF 1880. 



has also been added upon Yellow Fever, compiled chiefly from 

 Bartlett's "Fevers of the United States," edited by Alonzo 

 Clarke. 



Additions made to this edition have either been incorporated 

 in the text, enclosed in brackets, or placed at the end of their re- 

 spective sections ; so that any one having a former edition may 

 readily see whether there is any addition to any article which he 

 may desire to consult. 



Brief comparative tables of weights and thermometric scales 

 have also been introduced, to save readers the trouble of reducing 

 one to the other. 



NEW YORK, Jfay, 1880. 



