On Malaria. 303 
der families desolate in the open country, proceed from this inex+ 
haustible and self renovating source. 
- A remarkable instance in Sheffield, Mass. may serve for a sufi 
cient proof that this noxious influence is not confined to oriental or 
tropical countries, or even to southern Europe. Near that town are 
two large ponds, forming marshy grounds upon their margins, of con- 
siderable extent. In 1793, eighty out of one hundred and fifty per+ 
sons who lived within one and a half miles of the south pond, were 
attacked in one month with bilious remittents: and in 1795, of two 
hundred inhabitants, within three quarters of a mile of the north 
pond, a hundred and fifty were attacked with the same fever. Early 
in the spring of 1796, intermittents prevailed, and as the season ad- 
vanced, bilious remittents with dysentery, became epidemic within a 
mile of both ponds, not ten persons escaping of a hundred and fifty, 
while sickness was in every house in the settlement.* 
~ This department of physiology is indebted to Dr. McCulloch of 
Edinburgh, for the scientific manner in which he has traced anal- 
ogies—“ purified and balanced evidence”—classified and described 
diseases upon determinate principles—and discovered their causes 
amidst a chaos of empyricism and error; he has also arranged them 
under such generic forms as render dusts intelligible and recogniza- 
ble, under whatever circumstances. He substantiates his views on 
ony part of the subject, by authorities, examples and tables, and 
opinions are entitled to high confidence. If in any instance » she 
merits the charge of exaggeration, it is attributable to the 
number of disorders that had been viewed and treated as of a distinct 
and independent nature, which he found to be only symptoms and va~ 
tieties, “ simulations and variations” of a generic disease. 
similar in appearance, but proceeding from different causes, engaged 
his particular attention, as when apoplexy ushers in a remittent or in- 
termittent in place of the cold fit, if mistaken for ordinary apoplexy, 
the ordinary modes of treatment comiees it forks! So alsoy) in an ob- 
scure intermittent, with “a local rh intereostal 
muscles, if mistaken for pleurisy, an error of heqeinnciaiitny 
letting would be pernicious and destructive, while the proper 
treatment for intermittents would render the complaint trivial and ea- 
sily cured. *4 He further maintains that all supervening complaints 
* 
Webster 
‘ a of cca on Povr: Lond. Quarterly Jour. Sci. and Arts. Jan. to 
pril, 1 
