298 



NA TURE 



{Aug. 13, 1874 



simplest forms of the remotest age, equally simple forms may 

 have started into existence at all times down to the present 

 period. From the later original forms new ones may have been 

 evolved to speed towards the same goal as those which preceded 

 them. 



Feb. 17. — Dr. Ruschenberger, president, in the chair. — Prof. 

 Leidy made some remarks on the mode of reproduction 

 and growth of the Dtsmids. In illustration he described a 

 common species of Docidiuiu or PleHiottcuium. This consists of 

 a long cylindroid cell constricted at the middle and slightly ex- 

 panded each side of the constriction. When the plant is about 

 to duplicate itself the cell-wall divides transversely at the con- 

 striction. From the open end of each half-cell there protrudes a 

 colourless mass of protoplasm defined by the primordial utricle. 

 The protrusions of the half-cells adhere togetlier and continue to 

 grow. The bands of endochrome now extend into the protru- 

 sions and subsequently keep pace with their growth. The pro- 

 trusions continue to grow until they acquire the length and form 

 of the half-cells from which they started. Tiie exterior of the 

 new half-cells thus produced hardens or becomes a cell-wall like 

 that of the parent half-cells. In this condition two individuals 

 oi JDividium are frequently observed before separation. During 

 the growth of the new half-cells the circulation of granules in 

 the colourless protoplasm is quite active. In a species of 

 Docidium \\ mm. long by ^V i>™- broad, the growth of the new 

 half-cells was observed to be at the rate of about \ mm. in an 

 hour. 



March 3. — Dr. Ruschenberger, president, in the chair. — Prof. 

 Leidy read an extract from a letter relating to mammalian fossils 

 in California, from Dr. Lorenzo G. Vates, of Centreville, Ala- 

 meda County, California. 



March 10. — Dr. Ruschenberger, president, in the chair. — Ele- 

 vation of the trunk of trees. — Mr. Thomas Meehan suggested 

 on a lormer occasion tliat trees growing on a rock, by the natural 

 thickening of the roots beneath would lilt the tree four inches 

 in forty years. Since that time, however. Dr. Lapham, the 

 botanist, and State geologist of Wisconsin, had suggested to 

 him that frost gradually lifted trees so that the trunk would 

 sometimes appear in time to have elongated a foot or more. 

 Since Dr. Lapham had made the suggestions, he had examined 

 trees in the vicinity of Philadelphia and found unmistakable 

 evidence that large numbers of trees had been raised in the 

 manner stated. It was likely that one of the chief offices of 

 the tap roots was to guard the tree from this frost-lifting as much 

 as possible. His impression was that the trees of tropical cli- 

 mates had not near the development of tap roots which are found 

 in the more northern ones, but this was a matter for further in- 

 vestigation. 



March 24. — Dr. Ruschenberger, president, in the chair. — Prof. 

 Leidy read a paper on Actinophrys sol. 



Vienna 



Imperial Academy of Sciences, M-irch 26. — Prof. Freih. 

 von Lttingshausen presented a memoir On the history of the 

 development of terrestrial vegetation. The first part treats 

 of Tertiary floral elements and the genetic relation of these 

 to present flora ; the second, the elements of European flora. 

 — Dr. Schrotter spoke on tlie transformation of ordinary into 

 amorphous phosphorus, through action of electricity, and de- 

 scribed three forms of apparatus prepared by Dr. Geissler, 

 of Bonn, for the purpose. There is evidence that the change 

 is wrought neither by the light nor by the heat accompanying 

 the current, but by the electricity itself. — Dr. Meyer presented a 

 second paper On new and imperfectly known birds of New 

 Guinea and the islands of the Bay of Geelvinks. — Dr. From- 

 beck communicated a memoir On an extension of the doctrine of 

 sphere functions and the forms of development, from these, of 

 a function in infinite series. 



Paris 



Academy of Sciences, Aug. 3. — M. Bertrand in the chair. 

 — The following papers were communicated : — Double series of 

 drawings representing terrestrial cyclones and solar spots, 

 executed by M. Faye. The drawings are to be published in the 

 Memoires ; the present communication contains a detailed descrip- 

 tion of them. — Eighth note on guano, by M. E. Chevrcul. The 

 author has detected the following salts in guano ; — Ammonium 

 carbonate and chloride, calcium urate, phosphate, and oxalate ; 

 certain potassium salts of volatile organic acids. The following 

 douljle salts have been recognised : — Potassium ammonium 

 oxalate, putas.sium ammonium sulphate, sodium ammonium 



phosphate, and magnesium ammonium phosphate. — Note on a 

 meteorite which fell on May 20, 1874, in Turkey, at Virba, near 

 Vidin, by M. Daubree. The fall was accompanied by a loud 

 noise, and the mass, weighing 3 '6 kilogrs., penetrated i metre 

 into the soil. Analysis showed that the meteorite contained 

 nickel-iron, chrome-iron, ferric sulphide, and an insoluble 

 residue, probably containing enstatile. — Additional note on the 

 fall of meteorites which took place on July 23, 1872, in the dis- 

 trict of Saint-Amand (Loir-et-Cher), by M. Daubree. By an 

 attentive examination of the surlacc of the soil, four other 

 meteorites weighing respectively 3, 03, o'6, and 06 kilogrs. have 

 been discovered. — Blast of sirocco experienced in Algiers on 

 June 20, 1S74, and followed over a great part of Algeria, by M. 

 Cli. Samte-ClaireDeville. — Observations madeduringthelast days 

 of tire appearance of Coggia's comet ; a letter from P. A. Secchi to 

 the perpetual secretary. The author obtained undoubted evidence 

 of polarisation. The linear spectrum of the nucleus apparently 

 continuous was resolved by careful examination into a banded 

 spectrum, the interruptions of which were most apparent near 

 the bands of the second spectrum superposed upon the con- 

 tinuous spectrum of the nucleus. A drawing of the spectrum 

 accompanied the letter. — Indication of a method of estabUshing 

 the properties of the ether, by M. X. Kretz. — Reply to a former 

 note by M. Houyvet on the scheme for re-establishing a central 

 sea in Algeria, by M. E. Roudaire The author does not fear 

 that the evaporation would dry up the proposed sea into a salt 

 lake as suggested by M. Ilouyvet ; he is of opinion that such a 

 circumstance would be entirely prevented by the establishment of 

 an inferior counter current. — Memoir on the thermal effects of 

 magnetism, by M. A. Cazin. The author has determined ap- 

 proximately the magnetic equivalent of a caloru: — Researches on 

 explosive bodies ; explosion of powder ; by MM. Noble and F. 

 A. Abel ; continuation of first memoir. — Fourth note on the 

 electric conductivity of ligneous bodies, by M. T, du Moncel. 

 — On the passivity of iron, by M. P. de Reynon. The author 

 attempts to explain this ].)henomenon by a voltaic action 

 transferring oxygen to the iron, and thus polarising the surface 

 of this metal. — On some bismuth and tungsten minerals from 

 the Meymac mine (Correze), by M. Ad. Camot. — Observations 

 on the development of the periplieral nerves of the larv.x of 

 Batrachians and Salamanders, primary and secondary fibres, 

 M. Ch. Roget. — Reproduction by photography of difl'erent 

 crystallisations such as are seen under tlie microscope, by 

 M. J. Girard. — Note on the stratification of the tail of 

 Coggia's comet, by M. A. Barthclemy. — On isoterebenthene 

 from a physical point of view, by M. J. Riban. The author has 

 instituted comparisons between the physical properties of this 

 substance, terebene, and terebenthene. — Constitution of ordi- 

 nary brominated propylene, by M. E. Reboul. — Action of nitric 

 acid on paraffin ; different products obtained ; by M. A. G. 

 Pouchet. Among other substances, paraffiinc add (Cj^HjoNOio) 

 is obtained, which the author has examined in some detail. — On 

 the action of chloral on the blood, by MM. V. Feltz and E. 

 Ritter. — Observations on the hailstones which fell at Toulouse 

 during the storm of July 28, 1874, by M. N. Joly. — Reply to 

 M. Leymerie on the subject of the carboniferous limestone of the 

 Pyrenees and the St. Beat marbles, by M. F. Garrigou. — Ob- 

 servations of a bolide at Versailles on the evening of July 27, by 

 M. Martin de Brettes. — Observation of a bolide at Toulon on 

 July 27, by M. Lecourgeon. 



CONTENTS p^GB 



Iceland's Millenary 279 



Reci£nt Researches in PHOTOGiiAPHY. By R. Meldola, F.CS. \ 281 



Lady Barker's " Lessons on Cooking'* 283 



Maunder's '* Treasury of Natural History " 283 



Our Book Shelf 284 



Letters to the Editor :— 



The Woolwich Aeronautical Experiment. — W. de Fonvielle . . 285 

 Fogs, Field-ice, and Icebergs in the Atlantic— Capt Wm. W. 



Kiddle 285 



Science at Cambridge.— George Darwin 286 



Circulation of Apparatus and Scientific Works 286 



Sounding Flames. — Dr, T. Strethill Wright 286 



The French Association for the Advancement of Science . . "86 



The Comets. By J. R. Hind, F.R.S 287 



The Form of Comets, IV. By M. Faye (fTiM ///fw/m.'w/w) . . 287 



The American Ovster-Trade 2^0 



Rude Stone Monuments or Chambered Barrows, I By W. C* 



Notes * * * Ina 



U.S. Weather Maps .*.'.' 295 



Scientific Serials 3^6 



Societies and Academies ^g- 



