AGASSIZ crease of the reef. In the following summer he explored the state of New York with Prof. James Hall, and afterward he visited again the most important localities with his pupils. In 1852 he accepted a professorship of compara- tive anatomy in the medical college of Charles- ton, S. 0., which he retained for two successive winters, making at the same time a thorough study of the marine animals of that coast, and extending his excursions to Georgia and North Carolina ; but finding the climate injurious to his constitution, he resigned the situation, and returned to reside permanently at the north. In 1868 he was appointed a non-resident pro- fessor in Cornell university, at Ithaca, N. Y. Since 1855 his attention has been largely de- voted to the arrangement of the materials col- lected in these explorations. To form an ade- quate idea of the extent of his collections, it ought to be known that besides his own efforts, and the assistance he has derived from the young men accompanying him everywhere, he has been much assisted by the friends he has made in every state during his excursions. The collections embrace also the western coast ; he has regularly received large contributions from California through his brother-in-law, Mr. Thomas G. Gary, Jr., who has collected for him extensively there. The results of all these explorations and investigations are now publishing in the work entitled " Contributions to the Natural History of the United States." Four volumes out of ten of this extensive work have already passed through the press. The subscription list extends to the unexampled number of 2,500 names, in all parts of the United States; a magnificent support of a purely scientific undertaking, executed on a grand and expensive scale, and an appreciation of the labors of a great original investigator, such as has never before been exhibited to the world. Prof. Agassiz's eminence as a scientific man was early recognized in Europe. In 1836 he was elected into the academy of sciences in Paris and the royal society of London, and soon after received similar honors from all the other great learned societies in Europe and America. He has received from the academy of sciences in Paris the Monthyon prize for experimental physiology, and the Cuvier prize ; the Wollas- ton medal from the geological society of Lon- don ; and the medal of merit from the king of Prussia. He has been a copious contributor to the leading scientific journals of Europe and America, and has made numerous communica- tions to the learned societies of which he is an active member. In the United States, his ac- tivity has been most beneficial in the American scientific association, the American academy of arts and sciences, and the Boston natural history society, the proceedings and transactions of all of which have been constantly enriched from his boundless resources. He is a man of great physical vigor, but hik constant labors have more than once been followed by imperative calls for rest. The vacations of a naturalist 13 TOL. i. 13 AGATE 177 are often more productive than the term time of most men, and science lost nothing when in the winter of 1865 he accepted the liberal offer of a Boston merchant, who undertook to pro- vide for the entire expenses of six assistants and the transportation of specimens, if the va- cation journey should be to Brazil. The labors of his youth on the great Brazilian collections of Spix had created in him a strong desire to study the fauna of this region, and on the 1st of April, 1865, he started on an expedition whose results are seen in the immense collections now stored in the Cambridge museum. At Rio de Janeiro he was cordially welcomed by the em- peror and received all possible assistance from the Brazilian government, a river steamer be- ing assigned for his especial use. After some time devoted to excursions in the environs, during which he settled the disputed question of the existence of drift phenomena in the southern hemisphere, he sailed for Para, and thence ascended the Amazon to Tabatinga on the Peruvian frontier. Here the party divided, and while Agassiz went down the river again, stopping at Ega or Teffe", Manaos, and other points, to pursue his researches into the ichthyology of the region, some of his assistants continued the exploration of the upper waters. Returning to Rio after a year's absence, he made some interesting excursions among the Organ mountains, and in July, 1866, sailed for the United States. The narra- tive of this journey, written mainly by Mrs. Agassiz, was published in 1868 ; and one of his assistants two years later published the geolo- gical report of the survey. Since his return from Brazil Agassiz has made a short excur- sion to the Rocky mountains. His arduous labors in extending the museum of compara- tive zoology at Cambridge have again shown him the need of rest ; and early in December, 1871, he started on a voyage around Cape Horn in the coast survey steamer Hassler, in company with several other men of science. The results of this voyage, undertaken for deep- sea dredging, have already proved to be of great importance in the study of oceanic faunae. The influence of Agassiz upon the scien- tific development of the United States has been profound and far-reaching. He has called into energetic action the minds of a large body of young men of science, who are laboring in every field of investigation with the enthusiasm he has inspired in the methods he has taught, and whose faithful study has con- tributed largely to the works since published by the master. AGATE (from the river Achates, now Dirillo, in Sicily, near which it was found), one of the mod- ifications in which silica presents itself nearly in a state of purity, deposited, not crystalline, but massive and slightly transparent. Agate, onyx, chalcedony, carnelian, sard, chrysoprase, and many others are but varieties, differing only in external form and appearance from each other, of the one family, quartz. "When
