486 



Dr. Henry Kennedy read a paper on the progress of epi- 

 demics. 



The object of this paper was to show that a great general 

 law existed, which appeared to regulate the progress of all the 

 more wide-spread epidemics which have passed over Europe 

 within authentic records ; that this law exhibits a progressive 

 movement, and that this movement is from east, or south-east ; 

 to west, or north-west. 



The paper was illustrated by a printed chart, which 

 offered, in one view, an outline of almost all the great epi- 

 demics of which there is any account. The writer further 

 showed that, in the diseases of the lower animals, the same 

 law also obtained, and that in America the same had been 

 observed when the vegetable world was affected with blights. 



Notice was likewise taken of the fact that great cold 



had, on different occasions, been found to move from east to 



west. 



From these several facts the writer concluded that some 



general law exists, regulating the progress of epidemics ; and 



that the existence of this law must alter materially the views 



commonly held on the spread of epidemic sickness by either 



famine or contagion. 



The writer confined himself exclusively to the consideration 



of the general law, and said he hoped to be allowed, on some 



future occasion, to make some deductions from it. 



The President exhibited a diagram, representing the oscil- 

 lations of the barometer from December 18th, 1845, to the 

 present date. 



The Secretary read a letter from Robert James Graves, 

 Esq., M. D., containing a development of the method by 

 which he proposes to prevent the waste of water, by evapora- 

 tion, from tanks and reservoirs, in hot climates. 



