IV ADVERTISEMENT. 



The Fourth Lecture was delivered January 20, 1875, by 

 Dr. Horatio C. Wood, on "A Study of the Nature and Me- 

 chanism of Fever." Published by the Institution, February, 

 1875. 48 pp. 8vo. 



The Fifth Lecture was delivered February 17, 1876, by 

 Dr. William W. Keen, " On the Surgical Complications and 

 Sequels of the Continued Fevers." Published by the Institu- 

 tion, April, 1877. 72 pp. 8vo. 



JOSEPH HENRY, 



Secretary Smithsonian Institution. 



Smithsonian Institution, 



Washington, April, 1877. 



