ADVERTISEMENT, 



The "Toner Lectures" have been instituted at Washington, 

 T). C, by Joseph M. Toner, M. D., who has placed in charge of a 

 Board of Trustees, consisting of the Secretary of the Smithsonian 

 Institution, the Surgeon-General of the United States Array, the 

 Surgeon- General of the United States Navy, and the President 

 of the Medical Society of the District of Columbia, a fund, " the 

 interest of which is to be applied for at least two annual memoirs 

 or essays 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 knowledge, 

 they have been accepted for publication by the Smithsonian Insti- 

 tution in its " Miscellaneous Collections." 



SPENCEE F. BAIKD, 



Secretary Smithsonian Institution. 



Smithsonian Institution, 



Washington, June, 1880. 



(iii^ 



