field could be erected than to arrange for completing and caring for the work he loved, and to which he gave freely so many years of his life-namely, the Herbarium of the Academy of Natural Sciences. Mainly through his disinterested labors, it stands to-day scarcely second to any in the United States, containing, besides many unnamed, over 35,000 named species of flowering plants and ferns, the half of which have been verified and fastened down. "No one can probably be found to give the years of time he so freely gave. In order to carry on the work, and add to the collection, as exploring expeditions afford the opportunity, it has been proposed to establish a Redfield Memorial Herbarium Fund. "Mr. Redfield's will provides that his herbarium, minerals, shells and scientific works shall be sold to help the herbarium, thus furnishing a nucleus for the proposed fund. It is in mind to raise $20,000, but the interest of any sum that may be contributed can at once be made available. "Statements will be furnished from time to time to contributors, keeping them informed of the progress of the contributions. Checks may be made payable to the order of Thomas Meehan, Director, or Stewardson Brown, Treasurer, and mailed to either at the Academy of Natural Sciences, Nineteenth and Race streets, Philadelphia." THE MOTION OF CLOUDS. Ar a meeting of the Royal Meteorological Society, of London, on March 20th, Mr. W. N. Shaw, F. R. S., delivered a lecture on "The Motion of Clouds considered with reference to their mode of formation,' which was illustrated by experiments. The question proposed for consideration was how far the apparent motion of a cloud was a satisfactory indication of the motion of the air in which the cloud is formed. The moun tain cloud cap was cited as an instance of a stationary cloud formed in air moving sometimes with great rapidity; ground fog, thunder clouds and cumulus clouds were also referred to in this connection. The two causes of formation of cloud were next considered, viz.: (1) the mixing of masses of air at different temperatures, and (2) the dynamical cooling of air by the reduction of its pressure without supplying heat from the outside. The two methods of formation were illustrated by experiments. A sketch of the supposed motion of air near the centre of a cyclone showed the probability of the clouds formed by the mixing of air being carried along with the air after they formed, while when cloud is being formed by expansion circumstances connected with the formation of drops of water on the nuclei to be found in the air, and the maintenance of the particles in a state of suspension, make it probable that the apparent motion of such a cloud is a bad indication of the motion of the air. After describing some special cases, Mr. Shaw referred to the meteorological effects of the thermal disturbance which must be introduced by the condensation of water vapor, and he attributed the atmospheric disturbances accompanying tropical rains to this 160 hues. According to König, the dichromatic eye (green or red blind) can distinguish nearly the same number of hues, its accuracy being greater than that of the normal eye in certain regions. The seven colors inherited from Newton should be abandoned. Physically, any three wavelengths, sufficiently separated, suffice to produce all the colors; psychologically, we can distinguish about 160 hues, or, as Leonardo da Vinci stated, there are four distinct colors-red, yellow, green and blue. In the same paper König calculates that about 660 degrees of intensity or brightness can be distinguished between the light that is just visible and the light so intense as to be blinding. THE KARAKORAM HIMALAYAS. IN a lecture before the Imperial Institute of London, Mr. William Conway described the expedition to the Karakoram Himalayas made in 1892 under the auspices of the Royal Geographical Society, the Royal Society, the British Associotion, and the Government of India. The party consisted of the Hon. C. G. Bruce, Mr. A. D. M'Cormack, the lecturer, and two others, with an Alpine guide. The lecturer stated, according to the report in the London Times, that starting from Abbottabad, they went to Srinagar, the capital of Kashmir, thence by the Burzil pass to Astor and Bungi, in the Indus valley. The party followed the road to Gilgit, and a month was then spent in exploring the glaciers at the head of the Bagrot valley, and the great peaks in the neighborhood of Rakipushi. Returning to Gilgit they ascended the Hunza-Nagar valley, and visited the towns. From that point two long expeditions were made into the snowy region to the south and southeast before pushing forward to Hispar, which was at the foot of the longest glacier in the world outside the polar region. Dividing themDividing themselves into two parties, they made the first known passage of Europeans up the Nushik pass, and the first definitely recorded passage of the Hispar pass. The two parties united at Askole, in Baltistan, and, proceeding up the Braldo valley, arrived at the foot of the remarkable Baltoro glacier. Having forced their way to the very head of the glacier, they camped for two nights at an altitude of 20,000 ft. The Pioneer peak, which was 3,000 ft. above the camp, was also climbed, thus making, it was said, the highest ascent yet authentically recorded. Returning to Askole, they crossed the Skoro pass to Shigar and Skardo, whence they rode up the Indus valley to Leh, the capital of Ladak, or Western Tibet. The Zoji pass to Kashmir was traversed, and the party returned from Srinagar to England. GENERAL. PROFESSOR JAMES D. DANA died at New Haven, on April 14th, at the age of eightytwo years. THE sixty-fifth meeting of the British Association for the Advancement of Science will commence on Wednesday, the 11th of September, under the presidency of Sir Douglas Galton, well known for his works upon sanitation, and as an adviser of the Government in matters of sanitary engineering. An invitation is issued to the philosophers of England and other countries, by the Secretary, to support this meeting by personal assistance and written contributions. Americans who have been the guests of the British Association know how admirable the arrangements are for the conduct of these meetings and how, by invitation to the General Committee and the Sectional Committees, a visitor from a foreign country is soon made to feel that he is a part of this great scientific organism. AT the last meeting of the Victoria Institute, of London, Sir George Stokes, Bart, F. R. S., in the Chair, papers by Sir J. W. Dawson, C. M. G., F. R. S., Professors E. Hull, F. R. S., Parker and Duns, the Rev. G. Whidborne, and Mr. J. Slater, F. C. S., were read upon the questions in regard to natural selection and evolution, treated by Professor Huxley in his recent address on 'The Past and Present.' ON May 4th the Association for the Education of Women is to hold a general meeting in the Schools, Oxford, to consider the question of a petition to the University for the admission of women to the B. A. degree. DR. SHERRINGTON, now Superintendent of the Brown Institution, London, has been appointed to the George Holt chair of Physiology at Liverpool, vacant by the removal of Professor Gotch to Oxford. DR. H. WEBER, Professor of Mathematics in the University of Göttingen, has accepted a call to the University of Strassbourg, and Professor Hilbert, of Königsberg, has been called to the vacant chair in Göttingen. DR. E. R. L. GOULD has accepted a call to the Professorship of Statistics in the University of Chicago. MR. THEODORE T. GROOM, of St. John's College, Cambridge, has been appointed Professor of Natural History in the Royal Agricultural College, Cirencester, succeeding the late Professor Harker. DR. JOHANNES BRUMMER, Professor of Agriculture in the University of Jena, died recently at the age of forty-three years. THE death is announced of the Irish Naturalist, Mr. A. G. More. THE Appalachian Mountain Club, of Boston, announces the following excursions for 1895: April 19, Long Walk; May 11, May Walk-Nobscot Hill and Wayside Inn; May 30, Mt. Tom and Mt. Holyoke; July 1-8, Field Meeting-Seal Harbor, Mt. Desert; August, A probable excursion to the Selkirk mountains in British Columbia, occupying an entire month. A PSYCHOLOGICAL INDEX, being a bibliography of the literature of Psychology and cognate subjects for 1894, has been published by Macmillan & Co., as a supplement to the Psychological Review. The index has been compiled by Mr. Howard C. Warren, of Princeton College, and Dr. Livingston Farrand, of Columbia College. 1312 titles General are given, distributed as follows: 135, Genetic, Comparative and Individual Psychology 259, Anatomy and Physiology of the Nervous System 190, Sensation 107, Consciousness, Attention and Inhibition 176, Feeling 50, Movement and Volition 116, Abnormal 278. SOCIETIES AND ACADEMIES. THE MINNESOTA ACADEMY OF NATURAL SCIENCES, MINNEAPOLIS. JOINT MEETING WITH THE ST. PAUL ACADEMY OF SCIENCE. March 6th, in the rooms of the St. Paul Commercial Club. The Physical Features of the Lake of the Woods: PROFESSOR CONWAY MACMILLAN, State Botanist. Psychic Effects of the Weather: EDWARD S. Geology and Flora of the Mountain Region of Fatigue; its Cause and Social, Religious, Some Queer Forms of Shellfish: PROFESSOR H. L. OSBORN, Hamline University, St. Paul. C. W. HALL, Secretary. NEW YORK BRANCH OF THE AMERICAN FOLKLORE SOCIETY. On the evening of Saturday, April the 6th, the annual meeting of the New York Branch of the American Folk-Lore Society was held with the following result: The officers elected for the season of 1895-96 are as follows: President, Mr. E. Francis Hyde; First Vice-President, Mr. George B. Grinnell; Secretary and Treasurer, Mr. William Burnet Tuthill; as members of the Executive Council, Mrs. Henry Mrs. Henry Draper, Mrs. Mary J. Field and Mrs. E. Francis Hyde. The offices of Second VicePresident and the fourth lady member of the Executive Council were not filled, the places being held vacant for the action of the Executive Council. It was determined to hold the final meeting of the season on the evening of Tuesday, May the 7th, at the Hotel Waldorf. The speaker for the evening will be Dr. Matthews, of Washington, the subject being Navahoe Myths, illustrated by phonograph. It is also the intention of the Council to have four meetings during the coming season; three of them to be held at the Hotel Waldorf and one at the Museum of Natural History. At the meetings held at the Hotel Waldorf the members of the Society will be entertained after the reading of the paper. WM. B. TUTHILL, Secretary. AT the last meeting of the New York Mineralogical Club the following officers were elected for the ensuing year: President, George F. Kunz; Secretary, Professor Daniel S. Martin; Treasurer, J. W. Freckleton; Executive Committee, E. Schernikow, Dr. E. S. Arnold and Professor A. H. Chester; Curators, Professor R. P. Whitfield, Gilman S. Stanton and William Niven; Committee on Admissions, J. McCarthy and Frederick Kato; Committee on Executions, J. S. Walker, Professor D. S. Martin and Frederick Kato; Delegates to Scientific Alliance, George F. Kunz, Professor D. S. Martin and J. W. Schoonmaker. SCIENTIFIC JOURNALS. THE ASTROPHYSICAL JOURNAL, APRIL. Recent Researches on the Spectra of the Planets, II.: H. C. VOGEL. A summary of recent work on Jupiter, Saturn and Uranus. Photographic observations reveal no deviation in their spectra from that of the sun, but in the less refrangible region bands due to the absorption in the atmospheres of the planets have been recorded visually. A comparison of the visual spectrum of Uranus as mapped by Keeler and by Vogel shows little variation. Repeated observations on the red spot of Jupiter indicate no difference between its spectrum and that of the belts. From a study of the red region, the satellites probably have atmospheres similar to that of the primary. The spectra of Saturn and the ansæ of the ring on each side are identical in the more refrangible portion. That there is no absorption band at 2618 μ indicates the absence of an atmosphere around the rings. On the Periodic Changes of the Variable Star Z Herculis: N. C. DUNÉR. After discussing various observations upon this variable and giving its ephemeris, the writer concludes that Z Herculis is a connecting link between the algol and the Y Cygni types, differing from algol in having both components bright, and from l Cygni in that the components are of unequal brightness. It consists of two stars of equal size, one of which is twice as bright as the other. The stars revolve in 3 days, 23 hours, 48 minutes, 30 seconds, in an elliptical orbit whose semi-major axis is six times the diameter of the stars. The plane of the orbit passes through the sun. Preliminary Table of Solar Spectrum WaveLength, IV.: H. A. ROWLAND. The table is continued from 4266 to 4414. T. Andromeda: E. C. PICKERING. A study of later photographs indicate that the period of this variable, which was 281 days during 1891-1894, has changed for 1896. Eclipse of Jupiter's Fourth Satellite, February 19, 1895: E. C. PICKERING. A photometric observation before and after eclipse, compared with the second satellite. Spectrum of Mars: LEWIS E. JEWELL. A spectroscopic study of the water vapor of the earth's atmosphere shows that, unless the amount of water in the atmosphere of Mars is greater than that in the earth's atmosphere, it is useless to look for it there, with our present instruments. The chances for detecting oxygen and chlorophyl are better. On a New Method of Mapping the Solar Corona: GEORGE E. HALE. A method for using the differential bolometer. Evidence is offered that the heat radiation of the corona could be differentiated from that of the adjacent sky. If one member of the bolometer be exposed to a portion of the sky just beyond the coronal region, and the other member set successively on different parts of the coronal image, the galvanometer would indicate the varying radiation of heat intensity. Methods are also proposed for reducing the galvanometer readings to a form suitable for comparison with actual photographs of the corona. On a New Form of Spectroscope: C. PULFRICH. A translation from the Zeitschrift für Instrumentenkunde, describing a modification of the Littron spectroscope. Minor Contributions and Notes. Photographic Correcting Lens for Visual Telescopes: JAMES E. KEELER. The Color of Sirius in Ancient Times: W. T. LYNN. On the Variability of Es.-Birm. 281: T. E. ESPIN. The Displacement of Spectral Lines Caused by the Rotation of a Planet: JAMES E. KEELER. Dr. Pulfrich's Modification of the Littrow Spectroscope. A list of the titles of recent publications on astrophysical and allied subjects appearing since the last number is a feature of each issue. THE PHYSICAL REVIEW, MARCH-APRIL, 1895. THE leading article in this number of the Review is one by Dr. A. S. Mackenzie, On the attractions of Crystalline and Isotropic Masses at Small Distances The primary object of the paper is to give in de tail the methods and results of an investigation made for the purpose of determining whether, within the errors of observation, there is any deviation from the law of Newton in the case of attracting crystalline matter with reference to its optic axis, and the author gives also the results of some experiments made with a view to testing the application of the same law in the case of isotropic matter at small distances. Physicists do not yet fully appreciate the value of the ingenious device suggested by Professor Boys through which they have lately been able to use quartz fibres, which furnish a mode of suspending small masses far ahead of anything before made use of in stability or constancy of torsional resistance. Like many other apparently minor discoveries or inventions, the introduction of the quartz fiber has greatly enlarged the opportunities of the experimentalist, in that it provides a ready means of measuring forces so minute as to have been thought until recently quite beyond our reach. The solution of problems relating to near attractions has especially been forwarded by this device, as Professor Boys has himself shown in several able and important investigations. In the paper under consideration Dr. Mackenzie describes the apparatus used in studying the attraction of crystalline |