A discussion was held on the popular error of supposing that thunder and lightning are very rare in California, several members stating from their experience that both are common in the higher and more mountainous portions, at all seasons of the year, though rare in the lower regions. Dr. Behr stated that he had used the root of the _Aspidium argutum Kaulf._, successfully as an antidote for tape-worm since the year 1852, and with better results than attend the use of _A. filixmas_ of Europe. REGULAR MEETING, APRIL 4TH, 1864. President in the Chair. Present, ten members. Professor Whitney read a paper by Major Williamson, U. S. Engineer, giving the methods of determination and results of measurement by barometer of the depression of “Death Valley” below the level of the sea, made in 1860 by the Cal. and U. S. Boundary Commission. Death Valley was found to be the “sink” of the Armagoza River, which runs near the boundary, east of Owen’s Lake. The observations, are sufficient to show that the valley is from one hundred to two hundred feet lower than the level of the sea. REGULAR MEETING, APRIL 18TH, 1864. Dr. Trask in the Chair. Present, nine members. W. S. Brigham and Horace Mann were elected corresponding members, being about to proceed to the Sandwich Islands to make a thorough scientific exploration, under the auspices of the Boston Society of Natural History. The name of Mr. Louis Janin, elected in 1861 but accidentally omitted from the list of members, was directed to be published in the proceedings. Donations to the Cabinet: About two hundred specimens of rocks and ores from Humboldt River District, by Mr. Highton. Dr. Trask presented the following paper: Earthquakes in California from 1800 to 1864. BY JOHN B. TRASK. As the subject of earthquakes for some years past has engrossed much of the attention of scientific observers, I have, at the request of several members of the Academy, made out a complete report upon the occurrence of those phenomena upon this coast, as far as personal observation is concerned, and also so far only as we have authentic records prior to the occupancy of the present State of California by the American Government. The present paper contains, probably, all that can be verified, and places the subject in a form to which future reference may be made by other observers abroad; thus enabling them and ourselves also, to bring together the statistical facts which, it may be hoped, will help to form some rational theory in future years relating to the causal agency of those phenomena, as well as the physical laws governing their action.