242 ADDITIONAL NOTES ON CONTAGION. 



prevailed in New- York in 1795, proposed a distinction between contagious and infec- 

 tious diseases. He made use of the first term to denote such as are communicated under 

 any circumstances of atmosphere, whether pure or impure, as small pox, measles, &c. In- 

 fectious diseases he denominated those which are communicated in consequence of an im- 

 pure or vitiated state of the atmosphere, i. e. that the impurities of the atmosphere com- 

 municate the disease, not that the air contains any specific material derived from the 

 patient, except such as may be occasioned by want of cleanliness. This distinction, 

 proposed by Dr. Bayley, is, in my opinion, an approach nearer the truth thau any of his 

 predecessors have advanced, but it does not present us with a view of the whole truth, 

 upon the subject. The visiter or attendant contracts disease from one of two sources, 

 either from the filth of the sick room, or from a specific something issuing from the body 

 of the sick, the consequence of the peculiar disease under which he labours. If a person 

 visiting another ill of the yellow fever or plague, derives his disease from the impure 

 atmosphere of the apartment, I ask how it happens, that in all instances he contracts the 

 same disease with that of the person whom he visits ? Why is his disorder not an inter- 

 mittent, a remittent, jail fever, or dysentery, which are considered the usual produce of 

 filth ? If he derives any thing speciBc from the sick, his disease is then assuredly not to 

 be considered as occasioned by the atmosphere, but depending on the peculiar condition 

 of the fluids, or state of the system, induced by the action of a specific poison; in other 

 words, it is to be considered a contagious disease. The distinction proposed by Dr. 

 Bayley, inasmuch as it does not account for the communication of the peculiar form of 

 fever or disease which is thus propagated, I, therefore, consider to be insufficient to account 

 for the circumstances attending the communication of those diseases to which it is ap- 

 plied. That I may not be misunderstood, I will suppose A to be ill of dysentery, a dis- 

 ease well known to be attended with a peculiar train of symptoms ; he is in a small, con- 

 fined apartment, his person is neglected, the atmosphere around him is rendered impure 

 and offensive ; under these circumstances B visits him, and a few days after is also taken 

 sick with the same disease, attended in all respects with the same dangerous symptoms 

 which characterize the disorder of A. Dr. Bayley, and those who adopt the doctrine of 

 infection as opposed to contagion, consider the disease of B to proceed from the impu- 

 rities of the chamber, and not from any thing peculiar emanating or secreted from the 

 body of A. But as we may, without hazard, visit an equally filthy chamber where C 

 lies ill of cholera morbus, or D with a broken limb, I therefore ascribe the disease of B 

 to something more than the impure air of the chamber of A. I ascribe it to a peculiar 

 virus generated in his system by the disease under which he labours, and communicated 



