May 3. 1894J 



NA TURE 



23 



marble, (6) phyllite, &c., (7) "sericitic" gneiss. The third 

 section runs thus, using numbers to correspond with the last : — 

 (I) gneiss, (4) phyllite, (5) slabby marble, (6) phyllite, &c., (7) 

 "sericitic" gneis';. It must be remembered that on the slopes 

 of the Oberaip farther south, between the " sericitic " gneiss and 

 the '*Hospenthal Schists," another dark phyllite is found, 

 generally considered by the Swiss geologists to be carboniferous. 

 The marble in the third section is in places distinctly banded 

 with white mica, and passes on the northern side into fairly 

 normal mica schist and quartzose schist. The fourth section, 

 about a mile away, on the left bank of the Reuss valley, gives a 

 practically continuous section in phyllite and dark limestone, 

 without any marble. In the fifth section, rather more than a 

 mile farther, if any marble is present, it is very thin and shattered. 

 At Realp, about 3J miles farther, the next good section is 

 obtained. Here the rocks go in the following order (from the 

 northern side) : — (l) Gneiss ; (2) phyllite and limestone ; (3) sub- 

 crystalline limestone, looking very crushed ; (4) the marble ; (5) 

 phyllite, etc. ; (6) Hospenthal schists. The last group of sections 

 occurs near the Furka Pass. In the first, crossed by the high 

 road, there is no marble, but a little rauchwackeon the southern 

 side. The next one, on the slopes below the pass, seems to 

 show two masses of the marble parted by a subcrystalline lime- 

 stone like that at Realp, with phyllite above and below. Of 

 the two masses of marble the southern one can be traced right 

 across the pass, but the extent of the other is not so clear. 

 Examination of the marble mentioned above shows in all cases 

 that it has been considerably modified by pressure since it 

 became a crystalline rock. The author discussed the evidence 

 of these sections, and maintained that the hypothesis that the 

 marble is an older rock intercalated by thrust-faulting among 

 Jurassic strata leads to fewer difficulties than to consider it as 

 belonging to the same system. In the latter part of the paper 

 the results of a re examination of the ravine-section in the Val 

 Canaria, and of some studies of the south side of the Val 

 Bedretto are described, which, as the author maintains, con- 

 firm the view already expressed by him, viz. that the schists 

 with black garnets, mica, kyanite, dolomite, and calcite (the last 

 sometimes becoming marbles) are not altered Jurassic rocks but 

 are much older. — Notes on some trachytes, metamorphosed 

 tuffs, and other'rocks of igneous origin, on the Western Flank 

 of Dartmoor, by Lieut. -General C. A. McMahon. In this 

 paper the author noticed the occurrence of felsite and trachyte 

 at Sourton Tor ; of rhyolite and of aluminous serpentine at Was 

 Tor ; and of a dolerite at Brent Tor in the exact situation 

 indicated by Mr. Rutley as the probable position of the throat 

 of the Brent Tor volcano. The author described extensive beds 

 of tuffs at Sourton Tor and Melton, the matrix of which has 

 been converted, by contact-metamorphism, into what closely 

 resembles the base of a rhyolite, and which, in extreme cases, 

 exhibits fluxion-structure, or a structure closely resembling it. 

 The fragments included in this base were so numerous that six 

 or seven different species of lavas may be seen in a single slide ; 

 this fact, and a consideration of the extensive area over which 

 these beds extend, led the author to believe that these beds were 

 melamorphosed tuffs and not tufaceous lavas. He then described 

 some beds on the flank of Cock's Tor, which give evidence on 

 their weathered surface of an original laminated structure by 

 exhibiting a corded appearance like corduroy cloth. These 

 beds are composed of colourless augite, set in a base which in 

 ordinary light looks like a structureless glass, but which between 

 crossed nicols is seen to be an obscurely crystalline felspar. 

 The author compared these rocks with that portion of the 

 Lizard hornblende-schists for which a tufaceous origin was pro- 

 posed by De la Beche and other writers, including Prof. Bonney 

 and himself. He showed that the Lizard schists and the Cock's 

 Tor rocks agree in specific gravity and in some other character- 

 istics ; and he concluded that at Cock's Tor the first stage in 

 the conversion by contact-action of beds of fine volcanic ash into 

 hornblende-schist had been completed, and the final stage, due 

 to aqueous agencies, had just begun. 



Linnean Society, .\pril [9. — Prof. Stewart, President, in 

 the chair. — Sir Joseph Hooker exhibited a portrait of Jeremiah 

 Bentham, father of Jeremy and sir Samuel Bentham, born 

 1710, died 1792. — Dr. Prior exhibited specimens of Finns 

 Pinsapo with undeveloped catkins, like berries, and other 

 specimens of cinrfer; in flower. — Mr. J. R. Jackson exhibited 

 an Afghan knife, the sheath of which was bound with bark of 

 Caragana decorliciuis, selected on account of its bronze-like 



appearance, and gave some account of the various naiive uses 

 to which this bark is put. — -On behalf of Mr. George Mayor 

 and Mr. Y. R. Maw, some photographs of abnormally situated 

 nests of the robin were exhibited, one of which had been 

 built upon a book-shelf in one of the studies at Tunbridge 

 School, and another in an old tin teapot which had been flung 

 aside as useless, and had lodged in a poplar. — Mr. B. Shillitoe 

 exhibited and made remarks upon an abnormal hyacinth. — An 

 account of British Trap-door spiders was then given by Mr. F. 

 Knock, and by the aid of the oxy hydrogen lantern and some 

 excellent slides, their appearance and mode of life was graphic- 

 ally delineated and described. — In view of the approaching 

 anniversary meeting, the election of auditors was next proceeded 

 with, when Mr. Batters and Prof. Howes were nominated O'l 

 behalf of the Council, and Mr. Michael and Mr. J. Groves on 

 behalf of the Fellows, — In the absence of the author, Mr. 

 George Murray gave an account of Graf zu Solms-Laubich's 

 monograph of the Acetabulafieit , and the principal points were 

 illustrated with lantern slides. The limits of the group were 

 defined as excluding DasyclaJeir, and containing the living 

 genera Acetabtilaria, Polyphysa, Halicoryiu, and PUiophysa, 

 of which the author maintained only the first and third named. 

 The extinct forms, principally. -iciVH/rtriVr, were dealt with very 

 exhaustively, and their relation to the living ones indicated. 

 The paper consisted of a morphological account of all the 

 forms, as well as a detailed systematic review of them, and the 

 author's views of the relationship of the grasses to the forms of 

 Dasycladaeiz, Cymopolia, Neomeris, Bornetella, &c. , possessed 

 much novelty and interest. 



Paris. 



Academy of Sciences, April 23. — M. Loewy in the chair. 

 I —On an example of divergent successive approximations, by M. 

 Emile Picard. — Some preliminary remarks on the mechanism 

 for excretion of albuminoids, and the formation of urea in the 

 economy, by M. Armand Gautier. — Observations on the remarks 

 of M. Armand Gautier, by M. A. Chauveau. M. Berthelot 

 followed with a further observation, affirming M. Gautier's view 

 of the production of carbonic anhydride without direct oxidation 

 by means of free oxygen. — On the fossils collected at Mont- 

 saunesby M. Harle, by M. Albert Gaudry. The author brings 

 forward a number of these remains as proving the warm-tem- 

 perate climate obtaining at Montsauncs at the period to which 

 the remains of a monkey found there belong. — .\ note by M. 

 Potain explaining the scope and production of a work presented 

 — "Clinique medicale de la Charite." — On rolling movements, 

 by M. Hadamard. — On the agglomeration of explosive sub- 

 stances, byM. P. Vieille. The author continues his experiments 

 showing the effect on the speed and character of combustion of 

 the state of aggregation of a powder produced in its manufacture. 

 — On the variation of rotatory power under the influence of 

 temperature, by M. A. Le Bel. A decrease in annunt of 

 rotation is recorded, for several substances, with lowering of 

 temperature. This is not due to polymerisation, but may be 

 accounted for by a loss of mobility in the molecule — " la 

 molecule subirait alors comme unc sorte de congelation in- 

 terne." — On the electrical capacityof mercury and the capacities 

 for polarisation in general, by M. E. Bouty. — On the partition 

 of the discharge of a condenser between two conductors, one 

 having an interruption, by M. R. Swyngedauw. If the sparking 

 distance in a part of the unbranched circuit be I, and in the 

 interrupted branch I„, then with Ij constant the quantity of 

 electricity passing throu.;h the uninterrupted brancti increases 

 continuously with the distance I.,, becoming greater than the 

 total charge when L, exceeds a certain value. The value of L 

 giving this qua-tity equal to the total charge increases with I,. 

 — On the sodium derivative of ethyl acetoacetate, by M. de 

 Forcrand. The preparation of the pure derivative is described, 

 and, from experiments on the partially dehydrated salt, the 

 heat of hydration of the anhydrous substance is given as 419 

 Cal., and the heat of solution in 4 litres of water at 12' is found 

 to Be 4 39 Cal. — On the detection of "abrastol " in wines, by 

 M. L. Briand. — The parasitic Diptera of the .\cridians : Bom- 

 bylides. Larval "hypnodiC'" and metamorpho>is with period of 

 activity and period of repose, by M. Kiinckel d'Herculais. — 

 On the circulatory apparatus of Dreisseitsia polymorpha, by M. 

 Toureng. — Researches on the structure of lichens, by M. P. A. 

 Dangeard. — On ligneous tumours produced by an Ustilago 

 among the eucalyptus, by M. Paul Vuillemin. — Observations 

 apropos of the note by M. Calmette, relative to the poison of 



NO. 1279, VOL. 50] 



