ADVERTISEMENT. 



The "Toner Lectures" have been instituted at Washington, 

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

 a Board of Trustees, consisting of the Secretary of the Smith- 

 sonian Institution, 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 full}^ 

 established b}^ experiment or observation." 



As these lectures are intended to increase and diffuse knowl- 

 edge, they have been accepted for publication b}- the Smith- 

 sonian Institution in its " Miscellaneous Collections." 



SPENCER F. BAIRD, 



Secretary Smithsonian Institution. 



Smithsonian Institution, 



Washington, April, 1879. 



(iii ) 



