The general tendency clearly is for the vesicles to become flattened and arranged in layers, in planes perpendicular to the direction of the pressure from without.

It is clear that the same general tendency must be experienced even when there are bubbles of air in the vesicles, although no doubt the resultant effect would be to some extent influenced by the running down of water to the lowest part of each cavity.

I believe it will be found that these principles afford a satisfactory physical explanation of the origin of that beautiful veined structure which Prof. Forbes has shown to be an essential organic property of glaciers. Thus the first effect of pressure not equal in all directions, on a mass of snow, ought to be, according to the theory, to convert it into a stratified mass of layers of alternately clear and vesicular ice, perpendicular to the direction of maximum pressure. In his remarks "On the Conversion of the Névé into ice," ,"* Prof. Forbes says, "that the conversion into ice is simultaneous" (and in a particular case referred to "identical") "with the formation of the blue bands; .... and that these bands are formed where the pressure is most intense, and where the differential motion of the parts is a maximum, that is, near the walls of a glacier." He further states, that, after long doubt, he feels satisfied that the conversion of snow into ice is due to the effects of pressure on the loose and porous structure of the former; and he formally abandons the notion that the blue veins are due to the freezing of infiltrated water, or to any other cause than the kneading action of pressure. All the observations he describes seems to be in most complete accordance with the theory indicated above. Thus, in the thirteenth letter, he says, "the blue veins are formed where the pressure is most intense and the differential motion of the parts a

maximum."

Now the theory not only requires pressure, but requires difference of pressure in different directions to explain the stratification of the vesicles. Difference of pressure in different directions produces the "differential motion" referred to by Professor Forbes. Further, the difference of pressure in different directions must be continued until a very considerable amount of this differential motion, or distortion, has taken place, to produce any sensible degree of stratification in the vesicles. The abso lute amount of distortion experienced by any portion of the viscous mass is therefore an index of the persistence of the differential pressure, by the continued action of which the blue veins are induced. Hence also we see why blue veins are not formed in any mass, ever so deep, of snow resting in a hollow or corner.

*

6. Thoughts on Matter and Force, or marvels that encompass us, comprising suggestions illustrative of the theory of the earth and the universe; by THOMAS EWBANK, author of "Hydraulics and Mechanics," &c. 154 pp. 18mo. New York, 1858.-There are many excellent thoughts in this little work. But we cannot subscribe to its main doctrines, that expansion is the only effective moving power in a forming earth; that the earth's heat is due to pressure from gravitation; and that gravitation is a means of preventing any decrease of the mean temperature of a globe

*Thirteenth Letter on Glaciers, section (2), dated Dec. 1846. SECOND SERIES, VOL. XXVII, No. 80.-MARCII, 1859.

because heat is generated by pressure and by friction attending the circulation of the hot liquid. Expansion and contraction for a given change of temperature are equal in amount and also in mechanical power, and both may be sources of movements in the earth's crust. As regards the circulating liquid, the power causing the circulation is equivalent in amount of heat expended to the heat produced by the friction in the circulation, so that there can be no increase from this source. Since gravitation can produce no condensation except there be a loss of heat, it cannot be a means of augmenting the heat; and hence, whatever may be the amount at any moment, the sphere will still lose by radiation, and find its only possible means of compensation for the loss in external sources. The author touches on geological topics while no geologist, and therefore without being aware of the points that are to be met in the required explanations.

7. Shower of Mud at Corfu.-Dr. G. LAWSON describes a mud shower as having occurred at Corfu on the 21st of March, 1857. The day was squally and showery, and with the rain came down a light shower of mud which covered lightly the leaves of the trees and garden plants. Under microscopic examination the earthy material was found to consist mainly of quartz grains and not of minute organisms.

8. Notes on American Land Shells, No. 4; by W. G. BINNEY, (Proc. Acad. Nat. Sci. Philad., 1858, Nov.)-Mr. Binney in this paper gives a catalogue of American Terrestrial Mollusks, with full lists of synonyms, which will be found of great convenience to all interested in this subject. 9. Memoirs of the Geological Society of Great Britain, and of the Museum of Practical Geology. The Iron Ores of Great Britain. Part II, The Iron Ores of South Staffordshire; by J. BEALE JUKES, with various analyses, made under the direction of Dr. PERCY. 64 pp. 8vo. London, 1858.-The South Staffordshire iron works occur in an area of 50 square leagues about Dudley.

10. Smithsonian Report for 1857.-The Smithsonian Institution is doing for science what is done by a Royal Society abroad; and much more. For besides publishing elaborate papers and works which would fail of a publisher on account of the expense, it is giving activity to science over the land,-calling out zealous research, and full collections of observations and specimens, in explorations over the Rocky Mountains and the regions west,-making a gallery of Indian portraits, the Stanley collection being deposited there, with the prospect of its being purchased by government,-gathering a cabinet of the natural productions of the United States,-collecting a library of all the Transactions of foreign Societies and Journals, which is already remarkably complete and nearly as possible up to the date of publication, eliciting and issuing Reports on different departments of science,-sustaining a series of lectures at Washington through the winter, and making itself, for the great convenience of the country, a medium of communication in the way of publications, between the science of the two Continents. This Report gives a brief account of the publications and encouragements of researches and general progress of the Institution the past year; also lectures by Prof. Joseph LeConte and Prof. S. Alexander, communications on Meteorology, and a Translation of Dr. J. Müller's very valuable Report of recent progress in Physics, made by G. C. Schæffer.

It contains also the decision of the Board of Regents upon the charges brought by Prof. S. F. B. Morse (contained in Shaffner's Telegraph Companion in 1855) against Prof. Henry, implying his "consciously and willfully deviating from the truth and this too from unworthy and dishonorable motives" in his testimony respecting the claims of Mr. Morse touching the origin of the electro-magnetic telegraph. The charges were of so gross a character, that Professor Henry, under a sense of the responsibilities of his position as Secretary, deemed it incumbent on him to bring them before the Board. The report of the Committee of investigation pronounces the charges unsustained. Prof. Henry follows the report with a history of the discoveries that prepared the way for the telegraph.

11. Straw Lightning rods.-The power of straw as a conductor of electricity has been utilized in the south of France, no less than eighteen Communes in the neighborhood of Tarbes having been provided with conductors composed of straw. Experiments show that an electrical shock sufficiently powerful to kill an ox may be discharged by a single straw. Athen., No. 1630.

12. Tschudi.-Dr. Tschudi, the well-known traveller, has just returned from his last journey to Peru; the results of which will be submitted shortly to the public.-Ib.

OBITUARY.-Death of William C. Bond.-We are pained to announce the death of WILLIAM CRANCH BOND, Esq., the director of the Astronomical Observatory of Harvard College. He died at Cambridge, Mass., Jan. 29, 1859, aged 69. He was born in Portland, Me., Sept. 9, 1789. Before his appointment to the Cambridge Observatory, he had devoted himself with much industry, talent and success, not only to astronomical observations, but to the construction and improvement of optical instruments, in every detail of which he was well informed and practically skillful. Having gained a reputation as an observer at his private observatory in Dorchester, he was called to the charge of that in Cambridge, in 1839, before any buildings were erected. The great telescope was mounted June 24, 1847. In connection with his sons, he has used that great refractor with important results, in observations of the fixed stars, the nebulæ, and the planet Saturn. To his practical skill observers owe a piece of mechanism, called the "Spring Governor," by which time is visibly measured to a small fraction of a second. To the same skill in applying scientific knowledge to mechanical means was in a large part owing what is known in Europe as the "American method" of recording astronomical observations by electro-magnetism. He has been engaged with encouraging success in experiments for taking photographs of the stars by a camera attached to the great telescope. Before his appointment at Cambridge he was employed by the U. S. Government in making astronomical observations in connection with those of the South Sea Exploring Expedition. Mr. Bond's talents and acquirements as a skillful astronomer were duly appreciated not only in this country but also in Europe. In 1842 the honorary degree of Master of Arts was conferred on him by Harvard College. He was a member of the American Academy of Arts and Sciences, of the American Philosophical Society, and of the Royal Astronomical Society of London. By his death the College is deprived of a highly valued officer, and the scientific community of one of its most gifted and accomplished sons.-Boston Daily Advertiser.

Synopsis of the Report on Zoophytes; by JAMES D. DANA. 180 pp. 8vo. New Haven, 1859; containing descriptions of all the species in the Author's original 4to. Report, which is out of print.

H. L. BOWDITCH: Address on the Life and Character of James Deane, M.D., of Greenfield, Mass. 46 pp. 8vo.

Lieut. J. C. IVES: Colorado Exploring Expedition, Preliminary Report to Captain A. A. Humphreys, Topograph. Engineers. 12 pp. 8vo.

J. CASSIN: Mammalogy and Ornithology of the United States Exploring Expedition under Captain Wilkes, U. S. N., 1838-1842. 1 vol. 4to in 466 pages, with a folio atlas of 53 colored plates, 11 of mammals and 42 of birds.

F. T. CONINGTON: Handbook of Chemical Analysis. London: Longman & Co.The author adopts the notation of the Laurent school.

Sir R. I. MURCHISON: Geological Map of England and Wales, 16 inches by 14. London: E. Stanford. 58.-78. mounted in case.

ANDREW C. RAMSAY: Geological Map of England and Wales, 36 in. by 42. Scale 12 miles to the inch. London: E. Stanford. 258. in case. 30s. on rollers.

KNIPE: Geological Map of Scotland including the Shetland and Orkney Islands. London: E. Stanford. 258. mounted in case.

G. R. GREENOUGH: General Sketch of the Physical and Geological features of British India. Size 80 in. by 68, scale 25 miles to 1 inch. London: E. Stanford. 41. 48. on a roller and varnished or folded in a case.

LAKE PRICE: A manual of photographic manipulation; treating of the practice of the art in its various applications to nature, with 50 engravings on wood. London. 6s. 6d. J. Churchill.

J. RUSSELL HIND: An Astronomical Vocabulary. London. 18. 6d. J. W. Parker & Son,

G. W. LOWRY: Atlas of Physical and Historical Geography. Engraved under the direction of Prof. Ansted and Rev. C. G. Nicolay. London. 58. J. W. Parker & Son. JOHN MATTHEW JONES, Esq., assisted by Major J. W. Wedderburn and J. L. Hurdis, Esq. The Naturalist in Bermuda; a sketch of the geology, zoology, and botany of that remarkable group of islands, together with meteorological observations. London: Reeves and Turner.

H. P. PRESCOTT: Tobacco and its Adulterations. London: Van Voorst.-A work giving the means of distinguishing the kinds of leaves mixed with tobacco by microscopic and botanical evidence.

MILNE-EDWARDS, H.: Leçons sur la physiologie et l'anatomie comparée de l'homme et des animaux. T. IV. 1re parte. In-8. Victor Masson. 6fr.

LEUCKART, RDF.: Zur Kenntniss des Generationswechsels und der Parthenogenesis bei den Insekten. Mit 1 lith. Taf. Frankfurt a. M., 1858. Meidinger Sohn & Co. 8°, IV, 112 pp.

F. RITTER VON HAUER and FR. FOETTERLE: Geologische Uebersicht der Bergbaue der Osterreichischen Monarchie, mit einer vorwort von WILHELM HAIDINGER, 222 pp. 8vo. Vienna, 1855.

PROCEEDINGS ACAD. NAT. SCI. PHILADELPHIA, 1858, Nov. and Dec.-p. 188, Species of Cristatella from near Newport, R. L.; J. Leidy.-p. 190, Note on the Orthis insculpta of Hall; Christy.-p. 191, Birds of Hakodadi, collected by Dr. A. A. Henderson, U.S. N.; J. Cassin.-p. 197, Notes on American Land Shells, No. 4; W. G. Binney (see p. 300).-Plate 3 of the new Lepidopter, Argynnis astarte Fisher, well colored-p. 213, Hadrosaurus Foulkii, Reptile from the Cretaceous of New Jersey J. Leidy, W. P. Foulke, I. Lea.-p. 223, Ichthyological Notes; C. Girard. -Prodromus, &c. (Crustacea of the North Pacific Expedition) Anomoura; W. Stimpson.-p. 253, New Genera and species of N. American Lizards in the Museum of the Smithsonian Institution; S. F. Baird—p. 256, Remarks on the Lower Cretaceous beds of Kansas and Nebraska together with descriptions of some new species of Carboniferous fossils from the valley of Kansas river; Meck and Hoyden. ANNALS OF THE LYCEUM OF NATURAL HISTORY OF NEW YORK, Vol. VI, Sept. 1858. -p. 303, Synopsis of the Genus Achatinella; W. Newcomb.-p. 336, Remarks on certain species of North American Helicidæ (continued); T. Bland-p. 362. Synopsis of the Fresh Water Fishes of the Western portion of the Island of Trinidad, W. I.; T. Gill.