M<iy 24, 1877] 



NA TURE 



75 



solar eye-piece, which consisted of a prism with one lenticular 

 surface, cemented to another prism of different density ; the 

 quantity cif light reflected at the junction being in proportion to 

 the difference of the density of the two glasses. 



Linnean Society, May 3. — Prof Allman, F.R.S., president, 

 in the chair.— -Three foreign members were elected, and Mr. 

 James Paton, o( the Kelvin Grove Museum, Glasgow, was like- 

 wise elected an ordinary fellow.- — Specimens of abnormal prim- 

 roses were exhibited and commented on by Mr. Alf. W. Bennett. 

 — A paper on the perfoliate penny-cress ( Thlaspi perfoHatum) 

 was read by Mr. G. S. Boulger. This little plant has a very 

 limited Biitish area, viz., the neighbouring districts of Oxford- 

 shire and Gloucestershire, and according to our aullior Wilts ; 

 thus equally belonging to tlie Thames and Severn Valley jiro- 

 vinces. The altitude attained is from 360 to 500 feet above the 

 sea-level. — A conjoint memoir by Prof St. G. Mivart and the 

 Rev. R. Clarke on the sacral plexus and sacral vertebrae of 

 lizards was brought forward and discussed. They stated that it 

 has of late been recognised that in any attempt to reply to the 

 question, which vertebra of any lower animal answers to the 

 first sacral one of man, the nervous quite as much as the bone 

 relations require consideration. Our authors pass in review the 

 researches of Gegenbaur and Hoffmann, and then proceed to 

 describe their own dissections of the parts in question in the 

 chameleon, green lizard, iguana, monitor, and others. Insti- 

 tuting a comparison of the parts in the Batrachia, and of the 

 sacral region in bird;, they, in a somewhat technical summary, 

 announce that although often puzzling and complicated from 

 occasional variations in species and otherwise, the true sacral 

 vertebra; may be defined in all vertebrates above fishes, where 

 hind limbs are well developed. — The Secretary read a paper on 

 the genus AlveoliUs and some allied palaeozoic corals, by Prof. 

 Nicholson and Mr. R. Etheridge, jun. It seems from their re- 

 searches that the name Alveolites covers many forms whose 

 affinities, to say the least, are obscure. Discussing the charac'ers 

 and essential attributes of the genus in a historical rcsiimi, they 

 proceed by comparisons, microscopic and otherwise, to define 

 certain groups coming under previous definitions of Aiveoliks. 

 These are several species of the above and others of genera such 

 as Ornilcs, Brachypora, Chutilcs, &c. But moreover tliey state 

 that in several instance there appears much in common between 

 certain groups of Alveolites and Favositis, so that future investi- 

 gation may further necessitate the breaking down of what at 

 present may be regarded as but meagre lines of demarcation. 



Chemical Society, May 17. — W. Crookes, F.R.S., vice- 

 president in the chair. — The chairman announced that an extra- 

 ordinary general meeting would beheld on May 31 at 8 P.M. 

 The following papers were read : — On a slight modification of 

 Hofmann's vapour density apparatus, by M. M. P. Muir and S. 

 Suguira. The authors propose to omit the india-rubber plate of 

 the original apparatus, and mark off the height of the mercury 

 by a cathetometer and a slip of gummed paper. — Note on the fluid 

 coniained in a cavity in fluorspar, by J. \V. Mallet. The cavity 

 was 6 mm. by 2 '5 mm. by 1 mm. ; it contained water and a bubble. 

 On heating, the bubble became less mobile and the crystal 

 showed signs of incipient splitting. — Examination of substances 

 by the time method, by J. E. Ilannay. The author has deter- 

 mined the loss sustained by various hydrates in equal and suc- 

 cessive intervals of time, when sulimittecl, in a Liebig's drying 

 tube, to a current of air at various temperatures, and thus ob- 

 tains evidence of the existence of hitherto unknown hydrates. 

 Magnesium sulphate, when treated as above, loses S per cent, of 

 water in five minutes at 100° C. ; the loss is then much slower 

 and regular up to 29 per cent., when the rate of loss decreases 

 somewhat suddenly from the formation of a lower hydrate, which 

 loses water mucli more slowly. — On the dehydration of hydrates 

 by the time method, by W. Ramsay. The author examined the 

 hydrates of alumina, iron, copper, and lead.— On the transfor- 

 mation of aurin into rosaniline, by R. S. Dale and C. Schor- 

 lemmer ; by heating sulphuric acid .and pure phenol, and 

 gradually adding oxalic acid, pure aurin is formed ; by the action 

 of ammonia on aurin, red .aurin is produced, which, by the action 

 of alcoholic ammonia at 150° for several days is converted into 

 rosaniline. The authors consider aurin to be identical with 

 rosolic acid. — On certain bismuth compounds, Part VI., by 

 M. M. P. Muir. The author describes the preparation, &c., of 

 hypobismuthous oxide, bismuthous ox-ychloride and oxyhromidc, 

 and sulphbismuthyl chloride. — On the theory of the luminous 

 and non-luminous flame by J. Philippson. The author states 



what he considers to be the causes of the luminosity and non- 

 luminosity of flames. 



Zoological Society, May 15-— Prof. Mivart, F.R.S., vice- 

 president, in the chair. — Mr. Sclater made some remarks on the 

 progress and condition of the Zoological Gardens of Rotterdam, 

 Amsterdam, Antwerp, Brussels, and Ghent, which he hid just 

 visited. — A communication was read from Mr. G. S. Brady, 

 C. M. Z. S. , containing a monograph of the fossil Ostracoda of the 

 Antwerp Crag. — A communication was read from Dr. F. Day 

 containing a notice of the capture of a specimen of Coycgoiwus 

 oxyrliynchus, on the coast of Lincolnshire. — A communication 

 was read from the Marquis of Tweeddale, F.R. S., containing a 

 memoir on the birds of the genus Batrcichostonius. The author 

 came to the conclusion that there were seven recognisable species 

 of this difficult group inhabiting the Indian region, one of which 

 yet undescribed, was from the Philippines. The rule appeared 

 to be that the females were rufous from the nest, while the males 

 are brown and somewhat spotted. — Mr. Edward R. Alston read 

 the description of a shrew from Guatemala, which had been indi- 

 cated without being characterised by the late Dr. Gray, and for 

 which the name of Sorex veviv-pacis was now proposed. — Mr. A. 

 H. Garrod, F. R. S., read the second portion of a series of ]iapers 

 on the anatomy of passerine birds. — A communication was read 

 from Mr. T. E. Buckley containing remarks on the past and pre- 

 sent geographical distribution of the larger mammals of South 

 Africa. 



Entomological Society, M.iy 2. — J. W. Dunning, F.L.S., 

 vice-president, in the chair. — Messrs. H. J. Adams, Charlestrom, 

 Adams, and J. W. Slater were elected members of the Society. 

 — .Mr. Jenner Weir e.xhibited a large silken cocoon from the 

 Cape of Good Hope, supposed to be a spider's nest. On being 

 opened it was found to contain, among other debris, the skins of 

 a number of small spiders and the elytra of beetles of the genus 

 Moluris. Mr. Weir also exhibited a spider's nest from Mont- 

 serrat. — Mr. F. Grut exhibited a large species of Chelifer from 

 IS'orth Spain. — Sir Sydney Saunders exhibited a spider (Atypiis 

 sulzeri) taken on Hampstead Heath, where it is found inhabiting 

 tubes concealed under bushes. The tubes are about fourteen 

 inches in length and extend about ten inches beneath the surface 

 of the ground, the remainder projecting above the surface. The 

 same or an allied species had been observed by Mr. Jenner Weir 

 on the .South Downs. — Mr. Champion exhibited a series of Alaus 

 piiiryssi Irom Thaso Island. — Mr. CO. Waterhouse e.xhibited 

 specimens of the following insects from Tasmania : — Dohrnia 

 miraiiJa (Heteromerous beetle), Creopliilus crythroceplialus 

 (Staphylinidie)^ and Forjiciila erylhrocephala. The two last 

 species bore some mimetic resemblance to each other. — A paper 

 was read from Sir Sydney Saunders on the adult larva; of the 

 Stylopidic and their puparia, the author exhibiting specimens in 

 illustration. — Mr. H. W. Bates communicated a paper on Cera- 

 tor/iina quadriinaculala. Fab., and description of two new allied 

 species. Specimens of the new species and also of C. inorgani, 

 Westw., were exhibited. 



Physical Society, May 12. — Prof. G. C. Foster, president, 

 in the chair. — The following candidates were elected members 

 of the society : — Capt. R. V. Armstrong, R. E., Mr. W. H. M. 

 Christie, Lieut. N. Darwin, R.E., I'rof. E. Frankland, D.C.L., 

 F.R.S., Mr. H. F. Morley, Capt. R. G. Scott, R.E., and Mr. 

 Angus Weiss. Mr. S. P. Thompson read a paper on the chro- 

 matic observation of the eye in relation to the perception 01 

 distance. He discussed the various means of estimating dis- 

 tances by the eye, showing that when data for forming a judg- 

 ment by the associations of visible form or visible magnitude 

 fail, the judgment is founded on "aerial perspective," or else 

 upon the muscular sensation of adjustment to focus. As the 

 eye is, however, not achromatic, it cannot be in focus at the 

 same time for red rays and blue rays proceeding from one object, 

 but may be in focus if the blue rays come from a mere remote 

 object. This gives a definite basis to the axiom of painters that 

 blue is a retiring and red an advancing colour. Experiments 

 were described demonstrating the truth of this fact, and illustra- 

 tion was afforded of the chromatic aberration of the eye by 

 casting beams of light through a solution of permanganate of 

 potash upon a silvered ball, the illuminated point appearing red 

 with a blue surrounding halo to an eye adjusted to short focus, 

 but blue with a red halo to long focus. — Prof Guthrie referred 

 to the theory by which the apparent size of an object depends 

 on the amount of nervous excitement which it occasions, whether 

 this be due to the extent of the illuminated area or the 



