are the narratives of exploration among the Rocky mountains and in Oregon and California by J. C. Fremont; the reports of expeditions to the Red river of Louisiana, by Capt. R. B. Marcy; to Texas and New Mexico, by J. R. Bartlett; to Utah, by Capt. Howard Stansbury; to Arizona and the Gila river, by Lieut. Col. W. H. Emory; to the southern hemisphere, by Lieut. J. M. Gilliss; to Japan, by Commodore M. C. Perry; to the Rio de la Plata, by Lieut. T. S. Page; to the Amazon, by Lieuts. W. L. Herndon and L. Gibbon; to the Dead sea, by Lieut. W. F. Lynch; and the reports of the various expeditions for the survey of railroad routes to the Pacific. The chief arctic explorers are Elisha Kent Kane (1820-'57), whose narratives of the two Grinnell expeditions in search of Sir John Franklin are among the most interesting works of their class yet produced; I. I. Hayes, author of “An Arctic Boat Journey,” “The Open Polar Sea,” and other works; and C. F. Hall, author of “Arctic Researches,” whose melancholy fate is recorded in the “Arctic Experiences of Capt. G. E. Tyson,” edited by E. V. Blake.—The wide field of natural history has been explored during this period with results highly creditable to the sagacity and industry of American men of science. The most important work in this department is the “Birds of America,” by John James Audubon (1780-1851), remarkable for the vivacity of its descriptive passages and its splendid illustrations, American zoölogy has been further treated by Charles Lucien Bonaparte, Thomas Nuttall, J. P. Giraud, John Cassin, S. F. Baird, T. M. Brewer, and Elliott Coues, who have written on ornithology; by D. H. Storer, S. L. Mitchill, J. E. De Kay, and Le Sueur, on ichthyology; by Louis Agassiz, whose publications on comparative embryology, ichthyology, the geographical distribution of animals, and analogous subjects, are of the highest order of merit; by J. E. Holbrook, author of the most complete work on North American herpetology yet published; by Thomas Say, T. M. Harris, A. S. Packard, C. V. Riley, and J. L. Le Conte, who have written on entomology; and by Zadoc Thompson, A. A. Gould, B. S. Barton, T. A. Conrad, J. D. Dana, Isaac Lea, Jeffries Wyman, J. Bachman, J. E. De Kay, J. D. Godman, V. G. Audubon, S. Kneeland, A. E. Verrill, E. S. Morse, A. Agassiz, and others, who have illustrated various branches of the subject. The most eminent writers on botany are Asa Gray, author of several valuable elementary works and manuals; John Torrey, who prepared, sometimes in conjunction with Gray, the botanical reports of most of the United States exploring expeditions ; Amos Eaton, Stephen Elliott, C. S. Rafinesque, Thomas Nuttall, W. Darlington, A. B. Strong, Jacob Bigelow, D. J. Browne, Alphonso Wood, W. S. Sullivant, and George Thurber; on geology, President Edward Hitchcock, William Maclure, W. B. and H. D. Rogers, J. G. Percival, Ebenezer Emmons, T. Sterry Hunt, C. T. Jackson, D. D. Owen, J. D. Whitney, A. Winchell, F. V. Hayden, J. P. Lesley, C. F. Hartt, Clarence King, J. W. Foster, W. C. Redfield, C. H. Hitchcock, J. S. Newberry, James Hall, Joseph Leidy, H. C. Lea, W. W. Mather, O. C. Marsh, and C. D. Cope, of whom the last seven are also distinguished as palæontologists; and on mineralogy, Prof. J. D. Dana, author of several works on both geology and mineralogy, J. Ross Browne, P. Cleaveland, L. C. Beck, and C. U. Shepard. The writers on chemistry include Benjamin Silliman and Benjamin Silliman, jr., Robert Hare, C. T. Jackson, J. W. Draper, Joseph Henry, E. N. Horsford, John Torrey, E. L. Youmans, Campbell Morfit, and J. P. Cooke, jr. In other branches of natural science the most noted names are M. F. Maury, author of the “Physical Geography of the Sea” and other works, W. C. Redfield, J. P. Espy, and John Brocklesby, distinguished as meteorologists; J. W. Bailey, an eminent microscopist; A. D. Bache, for many years superintendent of the United States coast survey; Joseph Henry, who has made important discoveries in electro-magnetism; Samuel Forry and Lorin Blodget, climatologists; A. M. Mayer, distinguished for researches in acoustics; and S. C. Walker, B. A. Gould, G. P. Bond, O. M. Mitchel, Denison Olmsted, J. M. Gilliss, Hannah M. Peterson, Maria Mitchell, W. A. Norton, Elias Loomis, Joseph Winlock, D. Kirkwood, Simon Newcomb, C. H. F. Peters, J. C. Watson, T. H. Safford, S. P. Langley, and C. A. Young, distinguished chiefly as astronomers. The most eminent mathematician whom the country has yet produced is Nathaniel Bowditch (1773-1838), author of a translation, with a commentary, of Laplace's Mécanique céleste, and of the well known “Practical Navigator,” now in almost universal use. Other writers on mathematics are Benjamin Peirce, Charles Davies, C. H. Davis, and Thomas Hill. Many of the above named have been contributors to the reports and publications of the Smithsonian institution, or have participated in the scientific labors of the United States exploring expeditions and similar undertakings.—Of the numerous works on medicine and surgery produced during this period, it will suffice to mention the “Treatise on the Practice of Medicine,” by G. B. Wood; “Dispensatory of the United States,” by G. B. Wood and F. Bache; “Elements of Medical Jurisprudence,” by J. B. and T. Romeyn Beck; “Elements of Pathological Anatomy,” by S. D. Gross; “Materia Medica and Therapeutics,” by J. Eberle; “The Principles of Surgery,” by W. Gibson; “The Elements of Medicine,” by S. H. Dickson; “The Institutes of Medicine,” by Martyn Paine; the treatises on “Midwifery ” and “Diseases of Females,” by W. P. Dewees; the treatise on “Obstetrics,” by C. D. Meigs; the “Human Physiology ” and “Dictionary of Medical Science,” by R. Dunglison; “American Medical Botany” and “Nature in Disease,” by Jacob Bigelow; “Letters to a
