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 suffi- 

 cient proof that this noxious influence is not confined to oriental or 

 tropical countries, or even to southern Europe. Near that tovi^n 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 v^^ho 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 %, 

 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 them intelligible and recogniza- 

 ble, under whatever circumstances. He substantiates his views on 

 every part of the subject, by authorities, examples and tables, and 

 his opinions are entitled to high confidence. If in any instance he 

 merits the charge of exaggeration, it is attributable to the astonishing 

 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- 

 rieties, " simulations and variations " of a generic disease. Diseases 

 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 render it fatal. So also, in an ob- 

 scure intermittent, with " a local rheumatic affection of the intercostal 

 muscles, if mistaken for pleurisy, an error of frequent occurrence, 

 blood letting would be pernicious and destructive, while the proper 

 treatment for intermittents would render the complaint trivial and ea- 

 sily cured."! He further maintains that all supervening complaints 



* See Webster on Pestilence. 



t Review of McCulloch on Feveis. Loud. Qiiarterlv Jour. Sci. and Arts. Jan. to 

 April, 1828. 



