454 



NA TURE 



[Oct. I, 1874 



size relatively to the accompanying minerals. They commonly 

 occur in drusy cavities of the trachytes associated with specular 

 iron, hornblende, and augite. Details are given of the mode of 

 growth of the twins, their various forms and intimate combina- 

 tions. — Another paper by tlie same author describes a remark- 

 able crystal of calc-spar from Lake Superior. It is shown by 

 the formula: of the faces to be a form which is distinct from any 

 hitherto observed. It is transparent, and occurs with native 

 copper in amygdaloid melaphyre. — Another paper by Von Rath 

 is on a singular combination of rulilc and specular iron. The 

 fine spiculx of rutile are developed from between the plates of a 

 red kind of specular iron, and may be a subsequent formation. 

 It occurs in association with crystals of quartz and adularia in 

 clefts or druses in a fine grained talcose gneiss. — Von Rath's 

 next paper is On remarkable artificial crystals of pure copper. 

 At the meeting last year of the German Geological Society at 

 Weisbaden, Prof. v. Secbach exhibited crystalline copper which 

 Prof. Senft of Eisenach had obtained by galvanic electricity be- 

 tween small rings of zinc and copper. From an aggregation of 

 very small crystals a large mass was formed of the size of four 

 millimetres. The crystals are always twins, with the free end 

 most produced, and have a form which has not heretofore oc- 

 curred in native copper, though it has been found in galena and 

 binnite. The octahedral faces of the crystals are flat and 

 shining, while those of the icositetrahedron are curved and less 

 perfect. — Another paper discusses the hypersthene of Mont 

 Dore, described by Des Cloizeaux, a mineral which tliere occurs 

 in druses in trachyte in crystals three millimetres long, associated 

 with crystals of sanidine and tridymite. — Von Rath's last memoir 

 describes a new zeolite, named foresite, from the tourmaline 

 granite of Elba. — Prof. Tli. Petruschevsky, of St. Petersburg, 

 who has devoted himself since 1862 to the phenomena of mag- 

 netism, now publislies the results of his investigation on the 

 direct and indirect determination of the pole in magnets. Start- 

 ing with the basis of Biot's curve of magnetic intensity, he points 

 out that it is as easy to determine the pole theoretically as em- 

 pirically, details his two methods, and the apparatus where\N'itli 

 they are tested. He then considers the determination of the 

 pole in electro-magnets, and finally enumerates resuUs. — Dr. 

 (justav Junghann explains a simple law for llie development and 

 grouping of crystal zones. He introduces some maps of anorthite 

 into the memoir, in which the formula: of the faces are all set 

 down in tabular form in square spaces. — Ilerr G. Hagen con- 

 tributes a memoir On the resistance offered by tlie air to plane 

 discs moved through it. — Herr J. J. MiiUer examines one of the 

 Ilamiltonian theories of movement which underlies the principles 

 of mechanics. — Ilerr von Laspeyres has an interesting experi- 

 mental paper On the existing and a new thermostat, and Herr 

 Rammelsberg describes tlie crystalline form anl modifications of 

 selenium. — The most interesting reprinted p.aper is Terquem's 

 account of the vibroscope for_ accurately determining number of 

 vibrations. 



SOCIETIES AND ACADEMIES 



Leeds 



Naturalists' Field Club and Scientific Association, 

 Sept. 15. — Mr. Edward Thompson, vice-president, in the chair. 

 — Mr. James Abbott mentioned that he had gatliered Butomus 

 uml'fllatiis in flower at Ivirkstall, on Sept. 12. The plant had 

 not been noted in the Leeds district for upwards of twenty years 

 past, when it grew in the stream at the foot of Woodhouse Ridge. 

 — Mr. Henry Pocklington, in conjunction with Mr. James 

 Abbott, demonstrated the action of the induced current upon the 

 protoplasmic gyrations in the cells of I'lil/isiiciia sflralis, by 

 means of a simple electric slide and a small inductorium. The 

 eTect produced was very marked. The circulation of the proto- 

 plasm stopped almost instantly. It was, in fact, as was described 

 l>y o;ie of the members, as though a stro.ng "break "were put on. 

 Tlie protoplasm wascoiriigatcd by the rapid contractions induced, 

 and the resuUs taken altogether were of the most interesting 

 character. Mr. I'ocklinglon will probably communicate a more 

 complete description of his apparatus and its results at an early 

 date. 



Paris 



Academy of Sciences, Sept. 21. — M. Bertrand in the 

 chair. — The following papers were read : — Note on barium 

 sulphocarbonate, by M. P. Thenard. Since M. Dumas' pro 

 posal to use sulphocarbonates for the destiuction of r/:v//o.\ci\i 

 these salts liave acquired a new interest. The barium salt i 



easily prepared by agitating a strong solution of barium sulphide 

 with carbon disulphide. The author describes a process for 

 manufactuiing this salt on a large scale, and proposes to turn 

 his attention to the manufacture of the potassium salt. — On a 

 new mercury pump, by M. de Las Marismas. This apparatus 

 is slated to cost 35 francs, and to exhaust a receiver of six litres' 

 capacity to one millimetre pressure in four minutes ; all pressures 

 from that of the atmosphere up to an absolute vacuum can be 

 obtained, the gas contained in the receiver can be collected if 

 necessary, and a vacuum can be preserved indefinitely.— On the 

 action of alimentary or medicamental liquids on tin vessels con- 

 taining lead, by M. Fordos. The author has tried the action of 

 wine, vinegar, lemonade, cStc. , upon hospital vessels containing 

 10 per cent, of lead ; this latter metal v/as invariably found ia 

 the fluids used, and the author concludes that the us: of this alloy 

 may be attended with great danger. — Researches on the colour- 

 ing matters of garancine, by M. A. Kosenstiehl. The colouring 

 materials of garancine — alizarine, pseudopurjiurine, purpurine, and 

 its hydrate — have all been investigated in great detail by the 

 author. Purpurine and its hydrate are formed at the expense of 

 pseudopurpurine ; the products of the reduction of purpurine 

 have been studied, and two isomers of this body obtained, one of 

 which has been prepared by synthesis starting from benzoic acid. 

 Pure alizarine is prepared by healing the commercial substance 

 witli water to 200° C. for some hours, a small quantity of 

 caustic alkali being added. Impurities are totally destroyed 

 by this treatment, and the product of the operation is 

 further purified by frequent crystallisations. Pseudopurpurine 

 is a vei-y unstable body ; heating with water or alcohol trans- 

 forms it into a mixture of purpurine and its hydrate. From 

 the present researches it seems that garancine red and the rose 

 colouring matter yielded by garancine flov.crs cannot be obtained 

 from alizarine alone ; the presence of purpurine or its hydrate is 

 indispensable. The product of the action of reducing agents on 

 purpurine and its hydrate is purpuroxanthine, an isomeride of 

 alizarine. — New experiments on the nature of the sulphuretted 

 principle of the waters of Luchon, by M. F. Garrigou. This is 

 a reply to a paper by M. Filhol in the Compt. Rend, for Sept. 

 7. — Observations relating to a recent commu»ication by M. 

 Lichtenstein on some points in the natural history of Phvlloxcra 

 vastatrix, a letter from M. Balbi.ini. Tlic author again enforces 

 his views as to the non-identity of the Phylloxera of the vine 

 and of Qiwrciis couifcia. — M. P. Thenard made known to the 

 Academy the measures adopted by M. le PrelCt de Saone-et- 

 Loire on the approach of Phylloxera. — M. le Miniitre de 1' Agri- 

 culture et du Commerce and M. le Ministre des Finances con- 

 sulted the Academy on the employment of tobacco juice for the 

 destruction of Phylloxera. — Communications relating to Phyl- 

 loxera were also received from MM. J. Bond, H. de Martiny, R. 

 Delpit, &c. — Properties of the " implexes " of surfaces defined 

 by two characteristics, a geometrical note by M. Fouret. — On 

 luminous diffusion, by M. A. Lallemand. — On Warwickite, by 

 M. J. Lawrence Smith. The author assigns to this mineral the 

 formula Mg^lia + (MgFejTij- — On the ?•('/(■ played by gases in the 

 coagulation of blood, by MM. E. Mathieu and V. Urbain. — On 

 the movement in the bilabiate stigmata of the .Scrophulariacex', 

 Bignoniacea:, and Sesamea;, by M. E. Ileckel. — Observation 

 of a bolide at Versailles on the evening of the 14th of September, 

 by M . Martin de Brettes. 



CONTENTS 



Pags 



Hints ON Medical Studies 



Nomenclature OF DisE\SES 436 



Lbtthrs to the Editor ; — 



The Education of Women. — Lieut. -Col. Alex. Stkangr, F.R.S . 437 

 Double Rainbow.— Prof. Tait, F.K.S.E.; Prof. J. (Zv.zK\i-fA r. K- 



WELL, F.R.S. (H^M /llustratiou) 437 



Curious Rainbow. — T. W. Backhouss ; Arthur Schuster . . 437 



Mist Hows.— Howard Fox 438 



Carnivorous Plants — how to be obtained.— (J. H. Hol'KlNS ; . . 438 



Automatism of Animals — I. D. Wetterhan 43S 



Photographic Irradiation. — John Aitken 439 



Can Land-crabs Live under Water ?— J. C. Galton 439 



Salivary Glands of Cockroach — Chas. Workman 439 



The Austrian Polar Expedition 439 



The American Association FOR the Advancement OF Science . 441 

 Report of Prof. Parker's Hunterian Lectures ••On the 

 Structure and Development of the Vertebrate Skull," , 



VII. (,IVM llhistrations) 444 I 



Notes 446 



The British Association. Reports and Proceedings .... 449 



Scientific Serials 453 



Societies and Academies 454 



F.rratum. — V ol. X. p. 416, col. J, line 22 fioin bottom, lor ''Norway" 



