Feb. II, 1886] 



NA TURE 



359 



city of the air through the orifice under such con Jition^, was evi- 

 dent from an inspection of the tables, and more particularly of 

 Table V., where a pressure of six atmospheres acts as a vacuum 

 to a pressure of nine atmospheres. In this experiment it will 

 also be seen that 21 '22 cubic inches of air, of a constant density 

 of nine atmospheres (the equivalent of 5 lbs. of pressure), were 

 discharged successively into a vacuum and into atmospheres of 

 increasing densities up to six atmospheres, when the several 

 discharges were made in equal times, viz. 7 '5 seconds. Now, 

 the velocity for this time, as shown in Table I., is 1210 feet per 

 second for the contracted vein, and as the times were equal, so 

 were the velocities equal, for the successive discharges up to six 

 atmospheres. The velocity for low pressures, as I have shown 

 in Table III., is compounded of the rate of discharge into a 

 vacuum and the resistance of the atmosphere, and approximates 

 to the square roots of the pressures. For effective pressures 

 below I lb. above the atmosphere the rates of discharge are as 

 the square roots of the pressures, as has been shown by Dr. 

 Joule in the paper previously referred to. That the phenomenal 

 rates of discharge which I have described are manifested when- 

 ever slight differences of pressure exist between the discharging 

 and receiving atmosphere^, may be inferred from the familiar 

 experiment of fixing a perforated disk of cardboard by its centre 

 to the end of a small metal tube or a piece of tobacco-pipe ; 

 when a similar plain disk, placed on, or against the other, in- 

 stead of being driven off by a jet of air blown through the pipe, 

 is attracted to it. 



Sydney 

 Linnean Society of New South VVaUs, October 2S, 

 1885.— Mr. C. S. Wilkinson, F.L.S., Vice-President, in the 

 cliair. — The following papers were read : — Notes from the Aus- 

 tralian Museum, by R. von Lendenfeld, Ph.D. Note I. — The 

 vestibule space of Dcndrilla cavernosa. In this note a very 

 remarkable structure is described ; the sponge forms wide rami- 

 fied tubes with thin walls ; and the terminations of these tubes 

 are closed by sieves,"as in Etiplalella. Rings of sensitive and 

 ganglia cells are described round the pores in this membrane. 

 (_;iand cells similar to those of other Aplyiillida are also de- 

 scribed. Note 2. — Raphyrus hixoiiii, a new gigantic sponge 

 from Port Jackson. A sponge, weighing over 403 lbs. , was 

 recently dredged in Port Jackson. A detailed description of it 

 is given in this note. The author wishes to keep the two genera 

 Papillina and Raphyrus, combined by O. Schmidt and Norman, 

 distinct. He has found, besides the spicules known of the 

 European species, two other kinds in this Australian sponge. 

 The structure of the whole sponge is reticulate, as in the Aulen- 

 inre. Remarkable, very granular, amceboid cells, which are very 

 abundant around the inhalant lacnnes, are described as digestive 

 cells. Note 3. — Halme Unpens, n.sp. A sponge with peculiar 

 staining qualities. This is a sponge from Thursday Island, 

 which becomes blue after some time, and stains paper, &c. , 

 placed in the same spirit with it a remarkably dark blue. 

 The spirit remains light yellow. The author thinks that this 

 colour might be turned to practical account. Note 4. — A case 

 of mimicry. Four sponges are described and photographed in 

 this note. Two are Ceraospoii^iiv , and two are Monactinelltt, 

 Tne two former belong to the genus Chaliiiopsis. R. von L. ; the 

 two latter to the genus Dactylochalina. The author agrees with 

 ^■osmaer that the horny sponges have descended from the 

 Monacli)idlid siliceous sponges. I'orms like those described 

 connect the two groups. Their similarity in external appearance 

 is considered a case of mimicry. Whilst the internal structure 

 changed, and the sponge lost its spicules, it kept up a close 

 resemblance to the ancestral siliceous sponge which was defended 

 by its spicules. The case is a very interesting one. — Descrip- 

 tions of some new or rare Australian fishes, by E. P. Ramsay, 

 F. R. S.E., and J. Douglas-Ogilby. The species here described 

 are Pteroplatea australis, Sebastes scaber, and Platycephalus 

 arenarius, all new species, and Cirrhiticlithys t:rapJtidopterum 

 a.\\i Lepidotrig:la plcuracanlhica, species previously known. — On 

 the genus Trachichthys, by J. Douglas-Ogilby. A full de- 

 scription and synonymy of the genus is here given, the author 

 expressing an opinion that the T. australis, Shaw, and T. 

 jacksonensis, Macleay, are the same species. — Catalogue of 

 Australian Coleoptera, part ii., by Giorge Masters. The 

 families catalogued in this part are the Dytiscida, Gyrinidir, 

 Slaphylinidte, Pselaphidce, Paussidiv, Scydnanidm, Silphidiv, 

 Triclwpterygidie, Scaphididcv, HisteridiS, PItalacrida:, Nitidulidtv, 

 Trogositida, Colydidce, Rhysodidic, CucujidiT, Cryplophagide, 

 I.atrididiV, Mycetophagidt2, Dermcstid,r, Pyrrhid,v, Georyssida, 



Pariiide, JPeteroceridie — in all, 970 species. — The Plagiostomata 

 of the Pacific, partiii., by N. de Miklouho-Maclay and William 

 Macleay, F.L.S. Three fishes are here described: (l) A 

 Heterodoiilus from the Chinese Seas, identified as the true 

 Heterodontus zebra of Gray, hitherto looked upon as a synonym 

 o{ H. philUppi ; (2) a species of ray {RPyliobalis punctatits), taken 

 in 1S79 in the Lub or Hermit Iskands, north of the Admiralty 

 Group ; and (3) a ray from Sorry Island, north-west of the 

 Admiralties, which is placed in a new genus of the Tiygonidcs, 

 and named Discobatis marginipinnis. — Fourth addendum to the 

 Monograph of the Australian Hydromedusa;, by R. von Len- 

 denfeld, Ph.D. In this paper a new species of Hydra is 

 described, which possesses six arms, and on them cells, which 

 the author considers more nearly allied to the Palpocils of Sarsia 

 (Schuize) than the ganglia cells of Hydra. — Prof. Selenka's re- 

 searches into the development of the American opossum, by R. 

 von Lendenfeld, Ph.D. Prof. E. Selenka's most import.ant dis- 

 coveries regarding the concupiscence and the commencement of 

 the development of the embryo of this marsupial are enumerated 

 in this short preliminary report. — Second note on Macrodontism, 

 by N. de Miklouho-Maclay. The author states his opinion 

 about the very large teeth which he has observed in natives of 

 different islands of Melanesia. The results of observations 

 during his last two trips (1879 and 1882) to the Admiralty and 

 Lub Islands is the conclusion that the enlargement of the teeth 

 is nothing but an excessive accumulation of a special kind of 

 tartar deposited on the incisors and canines of the upper and 

 lower jaw. — Note on the "Keu" of the Maclay Coast, New 

 Guinea, by N. de Miklouho-Maclay. On the authority of the 

 late Dr. R. Scheffer, Director of the Botanical Garden of Buiten- 

 zorg, Java, the author states that t%uo species of Piper, allied to 

 Piper vietliysticuvi, but different from it, "were brought by him 

 in 1S73 from the Maclay Coast. The author gives a full de- 

 scription of the preparation of the " Keu "-drink on the Maclay 

 Coast, as well as of the eflfects of the same, which are more 

 soporific than intoxicating. He adds further some remarks 

 about the general use of the " Kava" root {Piper melhysticjim) 

 throughout the islands of the Pacific. 

 Paris 

 Academy of Sciences, February i.— M. Jurien de la 

 Graviere, President, in the chair. — On the theory of Mitchell's 

 screw-pile, and on the "vrille," a small apparatus terminating 

 in a sort of conic screw, used for making the scarfs of borings 

 with the screw-pile, by M. H. Resal. — On the measurement of 

 the velocity with v\'hich vibrations are propagated in the ground, 

 by MM. F. Fouque and Michel Levy. They describe an in- 

 strument which they have invented for the purpose of automa- 

 tically recording the velocity of propagation, as well as the 

 intensity and duration of vibrations such as those produced by 

 the blow of a Nasmyth hammer. — Note on some hyperelliptical 

 formulas, by M. Brioschi. — Report on M. Romieu's work 

 entitled " Essai sur les decans egyptiens," by M. Jules Oppert. 

 In this work the author has endeavoured with partial success to 

 determine the names of the th[rty-six so-called '* decans," stars 

 which played such a large part in ancient Egyptian astronomy. 

 — Determination of the constant of astronomic refraction by 

 meridian observations (continued), by M. .\-. Gaillot. — On the 

 integrals of total dift'erentials of the second species, by M. E. 

 Picard. — Geometrical theory of the articulated hyperboloid, by 

 M. A. Mannheim. —Experimental verification of a new geo- 

 metrical representation of the colour-sensations, by M. R. 

 Feret. After establishing certain properties of the colour-sen- 

 sations, and founding on them the principles of a new diagram 

 representing these sensations, the author proceeds to show that 

 the results furnished by experience harmonise at all points with 

 those anticipated theoretically. But although the theory leads 

 to the same equations as those already determined by Maxwell, 

 it differs essentially from them in so far as it is founded on the 

 rule of the parallelogram, and is independent of the notion of 

 the three fundamental colours. — Thermic researches on hypo- 

 phosphoric acid, by M. A. Joly. The thermic properties of the 

 two hydrates of phosphoric acid already determined are com- 

 pared with those of the various hydrates of phosphoric and 

 arsenic acid, the study of which the author has now completed. 

 Hypophosphoric acid is further compared with the other acids 

 of phosphorus and arsenic by studying its saturation with an 

 alkaline base, and two metallic bases, the oxide of manganese 

 and the oxide of silver. — Note on the indicators of the different 

 energies of the polybasic acids, by M. R. Engel. — A study of 

 chlorophyll, in connection with M. Regnard's induction that the 



