ADVEETISEMENT 



The "Toner Lectures" have been instituted at Washington 

 by Joseph M. Toner, M.D., who has pUxced in charge of a Board 

 of Trustees, of which the Secretary of the Smithsonian Insti- 

 tution is one, a fund, "the interest of which is to be applied 

 for at least two annual memoirs or essa^-s relative to some 

 branch of medical science, and containing some new truth 

 fully established by experiment or observation." 



As these lectures are intended to increase and diffuse knowl- 

 edge, they have been accepted for publication by the Smith- 

 sonian Institution in its " Miscellaneous Collections." 

 JOSEPH HENRY, 



Secretary Smithsonian Institution. 



Smithsonian Institution. 



Washington, November, 1873. 



(iii) 



