January 3, 1895J 



NA TURE 



223 



and will, by means of the reproduction of photographs, illustrate 

 some of the more imporlant physiographic features of Central 

 Australia. Baldwin Si'Encek. 



Palseontology at the Royal School of Mines. 



In reading the excellent review of the biography of Sir R. 

 Owen, which appeared in last week's Nature, I observe an 

 error which, though small, requires correction. It is stated 

 that when Owen surrendered his appointments at the College 

 of Surgeons he was "enabled to accept the lectureship on 

 Paleontology at the Royal School of Mines, in 1857." The 

 lecords of that Institution will s-how that Owen never held a 

 lectureship there, nor was he in any way connected with the 

 School. 



The large theatre of the Museum of Practical Geology was fre- 

 <iuently employed for other purposes than those of the School, by 

 permission of the Director-General ; and it was in virtue of such 

 permission from Sir Roderick Murchison that Prof. Owen used 

 the theatre for the delivery of his lectures on Palaeontology to 

 the public, in 1S57 and subsequently. T. H. Huxlev. 



Eastbourne, December 27, 1894. 



Eocene Fossils at Murren. 



I HAVK read with surprise the extracts from the letter 

 which you have received from Dr. Fellenberg on this sub- 

 ject. C3f course it has long been known that there are Eocene 

 strata at Murren. IJut below them lie calcareous rocks coloured 

 on the Swiss map as Malm, These are so described on p. 211 

 of the "Livret Guide," published by the International Geo- 

 logical Congress which met this autumn at Zurich. During 

 the subsequent excursion, under the able guidance of Prof. 

 Renevier, Prof. ^Golliez, and M. Lugeon, we were taken 

 to Murren and shown these rocks, and Prof. Golliez gave 

 us the reasons which had led some geologists to regard 

 them as Trias rather than Malm. It was in these cal- 

 careous bed.s that the layer containing nummulites was met 

 with. The train|was just starting, and we had to leave, but the 

 find excited so much interest that -M. Lugeon returned to Murren 

 the next day, with some of the party, and verified the exact 

 locality. John Lubbock. 



High Elms, Farnborough. 



The Use of the Globe in Crystallography. 



In your issue of December 20, Mr. Buchanan revives a graphic 

 method of cr)stallographic calculation which seems to have been 

 used in the early part of the century {ridd " Zur physischen 

 Krystallonomie, &c.," (irassmann, 1829, p. 37), and claims that 

 by use of the globe and nutroip/iire "every problem in the 

 geometry of crystals can be solved with ease and accuracy." 



Crystallographic angular measurements are said to be accurate 

 if subject to a probable error of less than two or three minutes, 

 and descriptions of inorganic substances are nowadays habitu- 

 ally published in which the probable errors are of this order. 

 Although no details of Mr. Buchanan's method are given, it 

 seems inconceivable that any graphic process of crystallographic 

 calculation, involving triangulation on a sphere, could be 

 accurately performed without the use of numberless tedious pre- 

 cautions and large and cumbrous apparatus. 



It is usually more easy to grasp a good plane diagram of any 

 solid figure than to understand and follow up explanations on 

 the solid figure itself; the use of the latter is liable to lead to 

 inaccuracy of expression and confusion of thought. Thus, 

 when the sphere is used, the real meaning of the points which 

 Mr. Buchanan describes as cataloguing the edges occurring on 

 crystals, is not at once seen ; using the plane projection, it is 

 immediately apparent that these points are characteristic, not 

 merely of the edges, but in a much wider sense, of the zones : 

 they are merely the poles of the zone circles. 



Further, the positions of the points representing the corners 

 are dependent on the iizts of the faces concerned, which, as we 

 teachers of crystallography are at infinite pains to impress on 

 our students, have no crystallographic signification ; these 

 points, then, are not chaiacleristic of the corners. 



Similarly, the rather complicated piece of reasoning respect- 

 ing "reciprocal inversion forms" simply yields the well-known 

 result that in the cubic system, the octahedron truncates the 

 corners of the cube. \VtLLIA^t I. Pope. 



Central Technical College, South Kensington. 



NO. 1314, V(.L. 51] 



"The Zoological Record." 



It has long been a matter of regret that the Zoological 

 Record is not sold in separate parts ; a specialist requiring any 

 one part being required to pay for all the others, though they 

 may be of no more use to him than so much waste-paper. 



In order to remedy, to some extent, this unfortunate stale of 

 things, I am proposing (if sufficient support is forthcoming) to 

 purchase the Zoological Accord as published, and to issue the 

 separated parts to subscribers. With this view, I would ask all 

 those desiring any part (of the volume just issued, or of past 

 volumes) of the Zoological Record, to communicate with me 

 a.i soon as possible, stating which part they would be willing to 

 subscribe (or. 



Although it is, of course, not intended to make a profit out of 

 this scheme, it will nevertheless be necessary to charge slightly 

 more for the separated parts than their proportionate value, as 

 some parts are almost certain to remain unsold. 



I am confident that this scheme will not in any way injure the 

 Zoological Society ; in fact, although they maintain the con- 

 trary, I am sure it would be to their advantage to issue the parts 

 separately, if necessary at a slightly higher rate. At present 

 subscribers are, I believe, mostly libraries and societies, re- 

 quiring the whole volume. These would, of course, continue to 

 subscribe for all parts, even if they were obtainable separately ; 

 while, on the other hand, all specialists who do not subscribe 

 under the present arrangements would be practically certain to 

 purchase those parts dealing with their own subjects, if obtain- 

 able at a moderate cost. If the proposed scheme meets with 

 support, it will go a long way towards proving the justice of the 

 foregoing contention, and in that case it will probably be 

 possible to induce the Zoological Society to grant the concession 

 for which many zoologists have for long been agitating. 



Royal College of Science, London. S. PACE. 



Gravitation. 



In answer to Dr. Lodge's letter, I may state that Newton in 

 his " Opticks " (Query 21) asks if an increase of density of the 

 ether outwards from bodies will not account for gravitation, 

 every body endeavouring to go from the denser parts of the 

 medium towards the rarer ; and if such increase of density may 

 not, even at great distances, be effective, provided the elastic 

 force of the medium be sufficiently great. 



I do not think a tensile ether is contemplated in this theory 

 of gravitation. Prof. Worthington's effect manifests itself only 

 in a tensile liquid, and this constitutes its suggesliveness in 

 connection with the hypothesis of a tensile ether. I have no 

 such definite ideas to advance as are put forward in the 

 " Opticks." J. J01.Y. 



Trinity College, Dublin. 



The Feigning of Death. 



The curious condition of apparent death, assumed by the 

 English grass snake, which Mr, G. E. Hadow describes 

 (NATUfiE, December 6, p. 127), is one that I have fre- 

 quently observed, but have always been puzzled to account 

 lor I hardly think that it has anything to do with simulation, 

 or that it is voluntary, since I have seen snakes so affected 

 when quite undisturbed in their cases. I have also observed 

 precisely the same state in the common Italian snake. In my 

 experience the condition only occurs in fairly hot weather, and 

 when the snake h.as not fed for some time. This seems to 

 point to a species of fainting fit, and I imagine that it is imme- 

 diately induced by a disturbance of the cerebral circulation. 



R. Harry Vincent. 



Leytonstone, December 30, 1S94. 



Peculiarities of Psychical Research. 



In reply to Prof. Pearson : (l) His remark about "scientific 

 acumen " was not made ii profos of M. Richet's experiments, 

 but of those of the S.P.R. ; and hardly any stress is laid on M. 

 Richet's results, either by Mr. Gurney or Mr. Podmore. Mr. 

 Gurney, on the contrary, expressly says : "Clearly no definite 

 conclusion could be based on such figures." But if Prof. 

 Pearson has made experiments which are equally striking in the 

 opposite sense, I wish he would publish them, or communicate 

 them to the S.P.R. (2) There was nothing in my letter to 

 indicate that I under-estimated the importance of "abnormal 

 distributions"; but I asked Prof. Pearson to say whether he 



