274 ADDITIONAL NOTES ON CONTAGION. 



NOTE I. (See page 233.) 



There is scarcely to be found on record a series of facts which so conclusively prove 

 the specific character of the pestilential or yellow fever, or points out the circumstances 

 under which it is propagated or extinguished, as those referred to in the text: e. g. we 

 have seen this disease introduced at the Wallabout on Long Island in the summer of 1804, 

 and the poison diffusing itself in that neighbourhood as far as the impurity of the air 

 extended; while the same disease conveyed, from the Wallabout into the city of New- 

 York, was instantly extinguished by means of the relative purity of the atmosphere, the 

 effect of the rigid system of police then observed. See American Med. and Phil. 

 Register, vol. 2. 



In like manner, in the summer of 1809, (see Statement by Dr. Gillespie, Amer. Med. 

 and Phil. Register, vol. 1.) the yellow fever was introduced and spread in the village of 

 Brooklyn, Long Island; at the same time that the city of New-York, within eight hun- 

 dred yards' distance, enjoyed the most perfect exemption from it; a fact which at once 

 disproves the dependence of yellow fever upon a general constitution of atmosphere 

 which many physicians believe to be necessary both for the origin and propagation of this 

 form of fever. We are led to the same conclusion by a perusal of the report relative 

 to the introduction of the yellow fever into the city of Amboy, New Jersey, in the 

 summer of 1811. See Amer. Med. and Phil. Register, vol. 3. 



NOTEK. (See page 234.) 



The following extract of a letter from the Rev. Dr. Samuel S. Smith, the late pre- 

 sident of Princeton College, shows that the fact 1 have stated of an interval taking place 

 between the first and the subsequent cases of fever is of so frequent occurrence, that 

 it even attracts the notice of those who are unconnected with the medical profession. 



Princeton, July 24th, 1808. 

 Dear Sir, 

 I have not any doubt but that yellow fever contains a specific contagion, essentially 

 variant from that of small pox, with which it has so often beeu compared in order to 



