ADDITIONAL NOTES ON CONTAGION. 271 



Extract of a Letter from Sir Gilbert Blane, M. D. frc. to (lie Hon. Rufus King, Esq, 

 Minister at the Court of St. James from the United States of America, dated 



London, 26th November, 1798. 

 Sir, 



I sit down to perform the promise I made you this morning, of putting on paper some 

 remarks on the nature of the yellow fever, and the means of preventing it. 



In doing this I shall chiefly confine myself to those views of it in which the magistrate 

 is concerned. The adopting of measures for the prevention of disease is one of the most 

 important duties of a wise and patriotic government ; and the discovery of these means, 

 as well as the efficiency of the steps to be taken, must depend on a thorough knowledge 

 of the causes by which it is excited and influenced. My opportunities upon actual ser- 

 vice in the West Indies in the late war, when physician to the fleet under the command 

 of Lord Rodney and Admiral Pigot, and my present official duty as a member of the 

 Medical Board of the Navy, have necessarily brought to my knowledge a number of 

 facts relating to this subject, and I shall be extremely happy if the communication of 

 some of the most important of them can throw any light, which may prove useful to the 

 American government in checking an evil so afflicting and calamitous. 



The first question that occurs with a view to preventive measures is, whether this 

 disease be infectious, and under what circumstances it is so? 



In those situations in which I observed it in the West Indies it was evidently so. 

 There was the most incontestible evidence of this, both on board of ships and at hospi- 

 tals, and the doubts which have been started on this point, seem to have arisen from the 

 operation of infection being blended with that of other causes, which must concur with 

 it in order to give it effect. 



But whatever doubts there may be on this subject in the West Indies, there can be 

 none in the climate of North America. This will be best proved and illustrated by an 

 example. 



On the 16th of May, 1795, the Thetis and Hussar frigates captured two French 

 armed ships from Guadaloupe on the coast of America. One of these had the yellow 

 fever on board, and out of fourteen men sent from the Hussar to take care of her, 

 nine died of this fever before she reached Halifax on the 28th of the same month, and 

 the five others were sent to the hospital sick of the same distemper. Part of the prison- 

 ers were removed on board of the Hussar, and though care was taken to select those 



