42 INTRODUCTION. 
In 1816, a new topic of inquiry was presented here, as well as in Europe, 
involving the question whether the human system was susceptible of the yellow 
fever a second time. Dr. Francis, then in London, addressed a letter of inquiry 
on the subject to the medical faculty of the United States; and the result of the 
testimony acquired, seemed to show that, after one visitation, the constitution has 
generally an exemption from that disease. Dr. ‘Townsend, in his treatise on the 
yellow fever as it manifested itself in 1822, corroborated this conclusion; but 
after all, on a point of such deep interest to humanity, further inquiry seems 
desirable. 
Dr. Hugh Williamson’s “Observations on the climate in different parts of 
America, compared with the climate in corresponding parts of the European con- 
tinent,” is a work of much interest. His exposition of the meliorating effects of 
cultivation of the earth upon the temperature of the country, is very cheering to 
the philanthropist. The disquisitions of Dr. Samuel Forry, on the climate of 
the United States, and its endemic influences, challenges the attention of the 
philosopher as well as of the physician. 
? ¢¢ 
A disease designated by several names, as “spotted fever,” “malignant typhus,” 
“typhoid pneumonia,’ and other appellations, prevailed extensively in 1812 
and 1813. Monographs on this pestilence were given to the public by North, 
Hosack, Hudson, Arnell, and several other contributors to the New-York Medical 
Repository, and to other periodical journals. 
The appearance of the cholera asphyxia, in 1832, at New-York and at Albany, 
and shortly afterwards its extensive ravages in other parts of this state, and the 
United States, awakened medical ardor, and the new enemy was encountered 
with energy and with clinical acumen. It numbered four thousand victims in New- 
York, and was proportionably not less fatal in Albany. Francis, Paine, McNaugh- 
ton and Reese were distinguished by their examinations into the origin and nature 
of the disease. It is deeply to be regretted that we are still without a direct and 
perfect history of this, and the various other epidemics which have prevailed at 
different periods. 'The influenza spread over our territory in 1807, in 1811, and 
