48o 



NA TURE 



[April 13, 1876 



niferous limestone of Derbyshire in the museum of the Geolo- 

 gical Survey, which displays numerous plates belonging to the 

 test of a large Echinoid, considered by him to be a new species 

 of the genus Melonites, hitherto regarded as peculiar to America. 

 The author proposed to call this species Melonites Etheridgii, 

 and he described it as possessing a more or less spheroidal test, 

 about seven inches in diameter, composed of very thick plates, 

 arranged in five ambulacral and five interambulacral areas, all 

 the plates being ornamented with minute tubercles for the sup- 

 port of spines. The interambulacral areas were probably about 

 twice as broad as the ambulacral, and composed (at the equator) 

 of about nine ranges of plates, the marginal ones pentagonal, the 

 rest hexagonal, articulating with each other by faces varying from 

 a right angle to one of 30°. The ambulacral areas were broad, 

 each formed ot two convex ribs separated by a meridional 

 depression running from mouth to anus, and each rib (half-area) 

 composed of six or seven ranges of irregular plates, each perfo- 

 rated by a pair of simple pores. The tubercles are minute, im- 

 perforate, without boss, and of two orders, the larger sur- 

 rounded by a smooth areola, bounded by an elevated ring. The 

 spines are small, tapering, coarsely sulcate, with a prominent 

 collar round the articular end. A second specimen exists in the 

 British Museum. The species differs strikingly from the North 

 American Alelonitis viultipcrns in the characters of the am- 

 bulacral areas, which have 12-14 ranges of plates, and are 

 divided by a meridional furrow in the new species, and 

 only eight ranges of plates, with a median ridge formed 

 of plates twice as large as the rest in M. multiporus. — 

 Note on the phosphates of the Laurentian and Cambrian rocks 

 of Canada, by Principal Dawson, F.R.S. The author described 

 the mode of occurrence of phosphatic deposits in various locali- 

 ties in Canada. Dark phosphatic nodules, containing fragments 

 of LingtiLv, abound in the Chazy formation at AUumette Island, 

 Grenville, Hawkesbury, and Lochiel. Similar nodules occur in 

 the Graptolite shales of the Quebec group at Point Levis, and in 

 limestones and conglomerates of the Lower Potsdam at Riviere 

 Quelle, Kamouraska, and elsewhere on the lower St. Laurence ; 

 these deposits also contain small phosphatic tubes resembling 

 Serpidites. The Acadian or Menevian group near St. John, 

 New Brunswick, contains layers of calcareous sandstone black- 

 ened with phosphatic matter, consisting of shells and fragments 

 of Lingulce, The author described the general character of the 

 phosphatic nodules examined by him at Kamouraska, and gave 

 the results of analyses made of others from various localities, 

 which Jurnished from 36 38 to 55 '65 per cent, of phosphate of 

 lime. A tube from Riviere Quelle gave 67 "53 per cent. The 

 author accepted Dr. Himt's view of the coprohtic nature of the 

 nodules, and inclined to extend this interpretation to the tubes. 

 The animals producing the coprolites could not be thought to 

 be vegetable feeders ; and he remarked that the animals inha- 

 biting the primordial seas employed phosphate of lime in the 

 formation of their hard parts, as had been shown to be the case 

 with Lingulce, Conularia, and the Crustaceans. The shells of 

 the genus Hyolithes also contain a considerable portion of phos- 

 phate of lime. Hence the carnivorous animals of the Cambrian 

 seas would probably produce phosphatic coprolites. With regard 

 to the Laurentian apatite deposits, the author stated that they, 

 to a great extent, form beds interstratified with the other mem- 

 bers of the series, chiefly in the upper part of the Lower Lauren- 

 lian above the Eozoon limestones. The mineral often forms 

 compact beds with little foreign matter, sometimes several feet 

 thick, but varying in this respect. Thin layers of apatite some- 

 times occur in the lines of bedding of the rock. Qccasionally 

 disseminated crystals are found throughout thick beds of lime- 

 stone, and even in beds of magnetite. The veins of apatite are 

 found in irregular fissures ; and as they are found principally in 

 the same parts of the seams which contain the beds, the author 

 regarded them as of secondary origin. The Laurentian apatite 

 presents a perfectly crystalline texture, and the containing strata 

 are highly metamorphosed. The author's arguments in favour 

 of its organic origin are derived from the supposed organic origin 

 of the iron-ores of the Laurentian, from the existence of Eozoon, 

 from the want of organic structure in the Silurian deposit de- 

 scribed by Mr. D. C. Davies, and the presence of associated 

 graphite in both cases, from the character of the Acadian linguli- 

 lerous sandstone, which might by metamorphism furnish a 

 pyroxenite rock with masses of apatite, like those of the Lauren- 

 tian series, and from the prevalence of animals with phosphatic 

 crusts in the Primordial age, and the probability that this occurred 

 also in the earlier Laurentian. The position of the phosphatic 

 deposits above the horizon of Eozoon is also adduced by the 



author as adding probability to the existence of organic agencies 

 at the time of their formation. 



Paris 

 Academy of Sciences, April 3. — Vice-Admiral Paris in 

 the chair.— The following papers were read : — On the displace- 

 ment of lines in the spectra of stars, produced by their motion 

 in space, letter from P. Secchi. The author tabulates a number 

 of the observations made by Huggins, Vogel, and himself, and 

 those at Greenwich Qbservatory, and shows there is considerable 

 contradiction in the results. Might there not, he asked, be 

 some cause of systematic error in the manner of observing or in 

 the instruments ? Comparing the dark line Y of Sirius with 

 the hydrogen line II /3 from a Geissler tube, he got always the 

 same result — a shortening of the Sirius waves (contrary to 

 Huggins), when the telescope was carried along by the clock- 

 work, and the assistant was at the seeker to keep it on a fixed 

 point, and corresponding to the slit of the spectroscope ; but if 

 the clock-work stopped, or the assistant deranged the position of 

 the star, the bright line was displaced and came into coincidence 

 with the star line. Dispensing with clock-work, the line was 

 found to be on one side or the other according as the star was 

 looked at on one side or the other of the axis of the telescope. A 

 change was also had on turning the spectroscope 180'' on its 

 axis. P. Secchi merely points out these possible sources of illu- 

 sion without trying to explain them. — Observations of sun-spots 

 made at the Toulouse Observatory in 1874 and 1875, by M. 

 Tisserand. In 1874, 237 spots were observed ; in 1875 there were 

 only 88. Of the 76 spots observed at least three times in 1874, 

 41 were in the boreal hemisphere, 35 in the austral, with a 

 mean latitude (+ or—) of JO°-5. Of the 29 observed three 

 times in 1875, 17 were in the boreal, 12 in the austral hemi- 

 sphere; the mean latitude was il°7, M. Tisserand tabulates 

 his observations with reference to diurnal rotation. — Testing for 

 vinic alcohol in mixtures, and especially in presence of wood 

 spirit, by MM. Alf. Riche and Ch. Bardy, — On the spermatia 

 of the Ascomycetes, their nature and physiological r6le, by M. 

 Max. Cornu. The spermatia were at first considered by M. 

 Tulasne as fecundating corpuscles ; and in support of this was 

 their apparent refusal to germinate in the same conditions as 

 three other sorts of spores. M. Cornu says he has obtained a 

 very complete germination of spermatia in certain cases. Some 

 tintes the action of pure water will suffice to bring them to vege- 

 tation, more often it is necessary to add nutritive elements. The 

 facts observed refute the old theory of fecundation, and the sim- 

 plification introduced into the number of reproductive organs 

 gives a grand unity to the polymorphism of Ascomycetes. 



CONTENTS Page 



A Reseakch Fund for the Chemical Society. By Dr. W. J. 



Russell, F.R.S 461 



Tait's " Recent Advances in Physical Science. By Prof. J. 



Clerk Maxwell, F.R.S 461 



Dr. Ball on Screws. By J. D. E 463 



Our Book Shelf :— 



Contributions to the Dresden Museum 464 



Bristow's " Table of British Sedimentary Strata " 464 



Mann's " Catechism of Chemistry " 464 



Hutchinson's " Summer Holidays in Brittany " 465 



Lbtters to thb Editmr : — 



Colour of Flowers Grown in the Dark. — H. C. Sorbv, F.R.S. . . 465 



']"he Ash Seed Screw. — Francis Darwin 465 



The Animal of Millepora.— Prof P. Martin Duncan, F.R.S. . 465 

 The Use of the Words "Weight" and "Mass." — Prof. Henry 



Hennessv 4G6 



The Physical Constitution of Steam. — Joseph John Murphv . . 466 



Coloured Solar Halos. — ^Joseph Gledhill 466 



" The Effect of the Sun's Rotation and the Moon's Revolution on 



the Earth's Magnetism." — Stephen W. Allen 466 



Metachromism. — W.^L Ackrovd 467 



Dr. Klein on the Small-pox of Sheep.— E. Klhin, F.R.S. . . . 467 

 Our Astronomical Column : — 



Gibers' Supposed Variable Star near 53 Virginis 467 



The April Meteors 467 



Prof. Huxley's Lectures on the Evidence as to the Origin of 



Existing Vertebrate Animals, IV 467 



On Safety Matches. By C Tomlinson, F.R.S 469' 



NoTB.s from Siberia. By Prof George Forbes 4^ 



The Dublin Societies 470 



Germany AND THE Loan Exhibition 470 



On A Modified Cardiograph (W-'jVA ///«j^>-a^jt>«) 47? 



Physical Science in Schooi.s. By James M. Wilson 4^ 



Notes ... 473 



Kxperimhntal Rbsearchbs on the Effects of Electrical Induc- 

 tion, FOR THE Purpose of Rectifying the Theory Commonly 



Adopted, 1L By Prof. Volpicblli 47| 



Scientific Serials 47* 



Societies and Academies 4fl 



