proceedings: botanical society 191 



strata of Mesozoic age, but some Paleozoic limestones are also exposed. 

 Igneous rocks both of intrusive and effusive origin occur at a number of 

 places and certain of them seem to have been closely associated with 

 the deposits of commercial value such as gold and quicksilver. Un- 

 consolidated deposits are widespread and throughout much of the 

 region mantle and hide the underlying bedrock. These deposits are 

 mainly of glacial and glacio-fluviatile origin, though lacustrine, fluvi- 

 atile, and volcanic ash deposits are also described. 



F. W. Clarke: The inorganic constituents of marine invertebrates. 

 Two hundred analyses of hard parts of corals, mollusks, echinoderms, 

 worm tubes, algae, etc., throw much light on the origin of magnesian 

 limestone and phosphatic rock. (No abstract; the complete paper 

 will be published as a Professional Paper of the U. S. Geological Survey). 



Carroll H. Wegemann, Secretary. 



THE BOTANICAL SOCIETY OF WASHINGTON 



The 111th regular meeting of the Botanical Society of Washington 

 was held in the Crystal Dining Room of the New Ebbitt Hotel, Wed- 

 nesday evening, March 8, 1916. Eighty-two members and 117 guests 

 were present. Mr. A. S. Hitchcock, president of the Society, pre- 

 sided. Dr. Rodney H. True, as retiring president, delivered an ad- 

 dress, an abstract of which is given below. A dinner preceded the 

 address, after which there was dancing. 



Relation of Thomas Jefferson to Botany: Rodney H. True. It is 

 not generally known that Thomas Jefferson, who was perhaps the 

 center of a more intense partisan activity than any other man of his 

 time, was at the same time a great lover of outdoor life and took a keen 

 interest in an amateur way in botany. Throughout his life he main- 

 tained a correspondence with many of the prominent botanists of his 

 time and exchanged garden plants with William Hamilton, Bernard 

 McMahon, John Bartram, and other gardening botanists. Like 

 many of his planter neighbors, Jefferson accumulated a rather extensive 

 collection of rare and interesting plants and built up what was perhaps 

 one of the best botanical libraries in the United States. He wrote 

 only one book dealing chiefly with matters of science, his Notes on 

 Virginia, printed while he was in France in 1784. This book dealt 

 with the State of Virginia in all its aspects and in proper chapters dis- 

 cussed the botany and natural history of the state. This book was 

 translated into the French and German languages and ran through many 

 editions during the first fifty years of our country's history. While 

 in France he kept in close touch with the various developments of 

 European science and wrote long letters to various American corre- 

 spondents, including friends at Harvard, Yale, and other institutions, 

 summarizing the most important results coming to his attention. His 

 belief that the future of the United States was closely connected with 

 the country beyond the Mississippi led him to endeavor to secure the 

 exploration of that country soon after the close of the Revolution. 



