one grain, and the liquid furnished chloride of potassium with chloride of aluminum. ON THE ABSORPTION OF CARBONIC ACID BY LEIBIG'S DILUTE SOLUTION OF PHOSPHATE OF SODA. BY PROFS. W. B. ROGERS AND R. E. ROGERS. Prof. R. E. ROGERS gave the results of experiments made by himself and brother, upon this subject, by a dilute solution of the common phosphate of soda, containing one grain of the salt to 100 grains of water referred to in Leibig's work, entitled, “The Chemistry of Food." By a peculiar form of apparatus, furnishing very accurate results, this saline solution has been found to absorb a far larger proportion of carbonic acid, than is attributed to it by Professor Leibig. The amount given by the latter is 138 per cent., while that found by the Professors R. for the solution at 60 degrees, was 207.9 per cent., and at blood heat, 153.05 per cent. The Section then adjourned to meet to-morrow at 9 A. M. Friday, September 22, 12 o'clock. The Association met agreeably to adjournment; WILLIAM C. REDFIELD, Esq., President, in the chair. The Secretary of the Section of General Physics reported, that the Section had been organized by the appointment of Prof. JOSEPH HENRY, Chairman, and Prof. BENJAMIN SILLIMAN, JR., Secretary, and that a Standing Committee had been appointed for said Section, composed of Prof. Wм. B. ROGERS, Prof. BENJAMIN PEIRCE, Prof. JAMES H. COFFIN, Prof. B. SILLIMAN, JR., and Prof. JOHN H. C. COFFIN. Also, that Prof. R. E. ROGERS had been appointed Assistant Secretary of the Section. He also reported, that the scientific proceedings which had taken place in the Section yesterday and this forenoon, were as follows: Prof. B. SILLIMAN, JR., reported for the Section on General Physics That Prof. COFFIN had read a Paper on Winds, being a report on that subject, compiled in conformity to an appointment made at a previous meeting of the Association of American Geologists. That a paper had been read by Profs. W. B. and R. E. ROGERS, on the Volatility of Potassa and Soda, and their Carbonates. That Prof. ALEXANDER had read a paper on Aberration of Light. The Secretary of the Section of Natural History reported the organization of that Section by the appointment of Prof. LOUIS AGASSIZ Chairman; Dr. R. W. GIBBES, Secretary; Dr. A. A. GOULD, Assistant Secretary: and, in addition to the above, Dr. S. H. DICKSON and Prof. JAMES HALL, as members of the Standing Committee. Dr. GIBBES also reported the scientific proceedings had in the Section of Natural History, during yesterday and to-day, as follows::Theory of the Geological Action of the Tides, by Lieut. C. H. DAVIS, U. S. Coast Survey. On the Local Distribution of Marine Animals, by M. DESor. On the Fishes of Lake Superior, by Prof. AGASSIZ. On the Foraminifera, derived from deep sea soundings, in the Coast Survey, by Prof. J. W. BAILEY. On the Tracks of Mollusca, as an evidence of Beaches in the Silurian period, by Prof. J. HALL. On the Geographical Distribution of Coleoptera, by Dr. J. L. LECONTE. The reports made by the Secretaries of the Sections were severally adopted. A communication from the officers of the University at Cambridge was received, inviting the Association to hold its next annual session in that city. Action upon the adoption of the proposal was postponed, and the invitation was referred to the Standing Committee. A motion was made, that the proceedings be published in the form of a Journal, which proposition, after a discussion, participated in by Messrs. S. W. ROBERTS, Dr. M. W. DICKESON, Prof. W. R. JOHNSON, Prof. L. AGASSIZ and others, was finally referred to the Standing Committee. The Chairman of the Standing Committee nominated for membership in the Association Dr. J. B. LINDSLEY, of Nashville, Tenn., and the vote being taken, the nomination was confirmed. A communication was received from the Philadelphia Athenæum, inviting the members of the Association to visit the rooms of their Institution during the session, which was, on motion, accepted. On motion, adjourned, to meet again at half-past 4 o'clock, this afternoon. Friday, September 22, 4 o'clock. The Association met pursuant to adjournment, WILLIAM C. REDFIELD, Esq., President, in the chair. The Chairman of the Standing Committee reported a resolution accepting the invitation of the officers of the University at Cambridge to hold the next Annual Meeting of the Association in that city, and recommending that the 14th of August, 1849, be the day set apart for such assembling. After a short discussion, and an explanation of the reasons for adopting that as the period of meeting, the resolution was adopted. Lieut. MAURY, of the U. S. Navy, then presented a communication ON THE WINDS AND CURRENTS OF THE OCEAN, of which the following is an abstract : Lieut. MAURY reminded the Association of its having appointed a committee, in 1844, to represent to the Secretary of the Navy the importance of the information which our public cruisers might collect with regard to the Gulf Stream, and other subjects of general interest. It was scarcely necessary to say, that the Secretary who had signalized his administration of the Navy by the most enlightened and liberal policy, with regard to the true interests of science, and of which the National Observatory and Dead Sea Expedition were monuments, gave to the representations of the committee the most respectful consideration. It was owing to an impulse which was thus given, that Lieutenant MAURY had been enabled to carry into effect a favourite idea, long entertained, of constructing a series of charts, which should give to each navigator, who would consult them, the benefit of the experience of all who had gone before him. as to the winds and currents, and the like, in any given part of the ocean. Charts of the North Atlantic, upon this plan, were exhibited before the Association. They are so constructed as to show at a glance the prevailing winds, currents, temperature of the water, &c., for every month in all parts of the ocean. The characters or symbols for the winds are so contrived, that they show, at once, both the direction and strength of the wind. To obtain the results thus exhibited, involved immense labour: many thousand old log-books had been overhauled, and the records of each, as to winds, temperature of the sea, variation of the compass, and force and set of currents, compared with all the rest. The results, so far, were of high interest and great value. They show that the trade-winds, in the North Atlantic, blow with more regularity on the American than on the African side of the Atlantic, owing, probably, to the fact, that in the latter case the sands and deserts which heat and rarify the air, are to windward; while, in the former, they are to leeward. It was also shown that the so called north-east trade winds prevail more from the northward, on the American than they do on the African side of the ocean, and that calms are much less frequent on this, than on that side of the ocean. By a peculiar manner of grouping the statistics, with regard to winds, these charts have led to the discovery of a region near the equator, and extending midway the Atlantic, from the shores of Africa, within which, instead of a N. E. trade-wind, as there is between the same parallels, in other parts of the ocean, there is a regular system of monsoons. The usual route of vessels, in the Atlantic, from the northern to the southern hemisphere, passes through this anomalous region. To get to it, vessels from the United States are in the habit of sailing nearly across the Atlantic, passing down near the Cape de Verds, and so on, under the impression that when they get within it, they should find the winds favorable for a S. W. course, to enable them to recross the Atlantic, with fair winds, and so pass down the coast of Brazil; whereas, the chart showed, that of all courses, the winds were there most unfavourable for a course to the southward. This discovery, with others, developed by the chart, has led to the suggestion of a new route, nearer, and through a region of better winds, to the equator. Seven vessels, which had tried this new route, had returned their log-books to the National Observatory, at Washington; and the result was, that the mean of the seven passages was 11 days, or about 25 per cent. less than the average length of passage by the usual route. The manner in which the charts were cut up, by the tracks of vessels, enabled him to speak confidently as to the existence of a number of vigias, and other dangers of doubtful position, which disfigure our best and most accurate general charts. Many of these were pronounced to have no real existence. Many curious and interesting facts were also exhibited concerning the temperature of the ocean. Among these was pointed out, off the I shores of South America, between the parallels of 35° and 40° S., a region of the ocean, in which the temperature is as high as that of our own Gulf Stream; whereas, in the middle of the ocean, and between the same parallels, the temperature of the water was not so great by 22°. This region of warm water was noted for gales of wind. It is the most stormy that the charts, which are only partially completed for the South Atlantic, had as yet indicated. The habitual neglect of the use of the water-thermometer among navigators, generally, had been felt as a matter of serious inconvenience in this undertaking. It is one of the most useful instruments in navigation. All mariners, especially those sailing out of New York and New England should bear in mind the importance of ascertaining the temperatures of the ocean; for New York owed her commercial prosperity, in a great degree, to a discovery that had been made with the water thermometer. At the time when Dr. Franklin, with this instrument, discovered the Gulf Stream, Charleston had more foreign trade than New York and all the New England States together. Charleston was then the half-way house between New and Old England. When a vessel, attempting to enter the Delaware or Sandy Hook, met a N. W. gale, or snow-storm, as at certain seasons she is so apt to do, instead of running off for a few hours into the Gulf Stream, to thaw and get warm, as she now does, she put off for Charleston or the West Indies, and there remained till the return of spring, before making another attempt. New York now has more direct trade in a week than Charleston has in a year. Perhaps Dr. Franklin, with his water-thermometer, and Jeremiah Thompson & Co., with their packet-ships, may be regarded as the two most powerful agents of the many concerned in this revolution in the course of trade. A beautiful instance this of the importance and bearings of a single fact, elicited by science from the works of nature. The frequent and general use of the water-thermometer, by navigators, seems to be the only means by which we may hope to arrive at a proper knowledge of the aqueous circulation of the globe-of the currents and isothermal lines of the ocean. The Secretary of the Navy had authorized copies of these charts to be given to every navigator who would return to the National Observatory, according to form, an abstract of his voyages. Several thousand sheets of the chart had already been distributed upon these |