2 14 



NA TURE 



\_Dec. 30, 1886 



Pt 



{P't 



P't 



hurricane of March 3-4, l8S6, over the Fiji Islands, by Mr. 

 R. L. Holmes, F. R.Met.Soc. This storm was the most de- 

 structive that has ever b^en known to occur in the Fiji group. 

 The lowest barometer reading was 27 '54 inches at Vuna, in 

 Taviuni. The storm was accompanied by a great wave from 

 18 to 30 feet in height, which swept over the land and caused 

 an immense amount of damage. It was reported that fifty 

 vessels were wrecked and sixty-four lives lost during this hurri- 

 cane. — Results of meteorological observations made at the 

 Military Cemetery, Scutari, Constantinople, 1866-85, by Mr. 

 W. H. Lyne. The annual mean temperature is 58°'4 ; the 

 highest temperature registered was I03'''6 on June 22, and the 

 lowest I3°'0, on January 25, both in 1869. The annual rainfall 

 is 29^29 inches ; the greatest fall in one day was 4 '06 inches on 

 September 25, 1866. 



Physical Society, December n. — Prof. McLeod, Vice- 

 President, in the chair. — W. Natanson, Ed. Natanson, the 

 Ho.n. R. Abercromby, Jul. Verteimer, and H. M. Elder were 

 elected Members of the Society. — The following papers were 

 then read : — On the influence of change of condition from the 

 liquid to the solid state on vapour-pressure, by Prof. W. Ram- 

 say, Ph.D., and Sydney Young, D.Sc, read by Dr. Young. 

 The authors refer to some experiments published in IVifdema nit's 

 Annalen, vol. xxviii. p. 400, by W. Fischer, on the above sub- 

 ject, which show that the vapour-pressure of ice and solid benzene 

 are less than those of water and liquid benzene at the same tem- 

 peratures. By using the formula p = a + lit + ct- to express 

 the relation between the pressure and temperature of saturated 

 vapours, Fischer arrives at the absurd result that the vapour- 

 pressure of liquid benzene is not identical with that of solid 

 benzene at melting-point. If the above formula be replaced 

 by log p = a + hat, it is shown that the anomaly disappears. 

 The authors have measured the vapour-pressures of solid and 

 liquid benzene by the dynamical method, and obtain results 

 agreeing closely with those of Fischer determined statically. 

 They also calculate the vapour-pressure of solid benzene from 

 that of the liquid, using the formula — 



■ Vt-i + Ft-i \ 

 f^f-k )' 



where Pt .and P'f are the vapour-pressures of the solid and liquid at 

 temperature/, F/ - >, = heat of vaporisation of liquid, and Pi - k 

 = heat of fusion of solid at temperature / - i. The numbers so 

 obtained are in accordance with those determined e.xperimentally. 

 — On the nature of liquids as shown by the thermal properties of 

 stable and dissociable bodies, by the same authors, read by Prof. 

 Ramsay. From experiments on the vap jur-density and heat of 

 vaporisation of stable and dissociable bodies, the authors arrive 

 at two important results: (l) that for stable bodies, such as 

 alohol and ether, the density of their saturated vapours increases 

 with rise of temperature, whereas for bodies such as acetic acid 

 and nitric peroxide the vapour-density attains a minimum at a 

 certain temperature, and increases with either rise or fall of tem- 

 perature ; (2) the heat of vaporisation of alcohol decreases with 

 rise of temperature, but that of acetic acid attains a maximum at 

 about iio'C, and decreases with rise or fall of temperatui'e. 

 From these results the authors seek to prove that the difference 

 between stable liquids and their vapours consists in the I'elative 

 proximity of the molecules, this proximity being greater in 

 liquids than gases, and that the molecules of stable liquids 

 are not more complex than those of their gases. Prof. 

 Pickering dissented from this view, and thought that the 

 molecules of liquids are aggregations or compounds of those 

 of the gases. In answer to inquiries by the authors, Mr. 

 Lewis Wright said that bodies which rotate the plane of 

 polarisation of light when in the liquid state also rotate it in a 

 proportionate degree when gaseous ; and Capt. Abney remarked 

 that stable liquids and their vapours give similar absorption- 

 spectra, whereas those of dissociable bodies differ considerably. 

 Both these facts seem to support the view put forward by the 

 authors. — An account of Cauchy's theory of reflection and refrac- 

 tion of light, by Mr. James Walker, M.A. This paper is 

 intended as a statement of tlie work previously done in the 

 subject, and gives references to the original papers and " repro- 

 ductions, "&c., which will be of great value to persons studying this 

 important branch of the theory of optics. — Mr. Shelford Bidwell 

 exhibited and described a voltaic cell, in which the electrolyte is 

 dry peroxide of lead. It consists of carefully dried peroxide 

 placed between plates of lead and sodium, and gives a compara- 



tively strong current, which passes from the sodium to the lead 

 within the cell. 



Cambridge 

 Philosophical Society, November 8. — Mr. Trot'er, Presi- 

 dent, in the chair, — The following communications were made : — 

 On the coelum and body-cavity of Peripatus and the Arthropoda, 

 by Mr. A. Sedgwick. — Note on the "vesicular vessels" of the 

 onion, by S. H. Vines, M.A. Christ's, and A. B. Rendle, St. 

 John's. In investigating the vesicular organs with the object 

 of determining whether or not the transverse wall^ are perforated 

 so as to place the cavities of successive segments in communica- 

 tion, the authors observed that, in the quiescent winter condition 

 of the bulb, there are patches of callus — easily made conspicuous 

 by staining with corallin — on the transverse walls. From this 

 they infer that the transverse walls are perforated, the canals 

 through them being open in the active, and closed by callus in 

 the quiescent, condition of the bulb, just as is the case with 

 si;ve-tubes. This inference has, however, to be confirmed by 

 an investigation of the bulb in the active condition The authors 

 also observed that each segment of a vesicular vessel contains a 

 large nucleus. — On EpicUmmydia lusitanica, a new species of 

 Alga, by Mr. M. C. Potter. During August and September, the 

 author, with assistance from the Worts Travelling Scholars' 

 Fund, investigated the life-history of a new species of Alga, now 

 named Epiclenimydia lusitanica, which lives on the backs of 

 the tortoises inhabiting the pools of Southern Europe. This 

 Alga, which to the naked eye appears as small green roundish 

 patches, is found to consist of a number of cells closely applied 

 to tortoise-shell, but which are only a few layers deep, here and 

 there penetrating into the tortoise-shell and causing it to flake 

 off. The cells next to the tortoise-shell always force their way 

 into any available crack, where they divide, and thus penetrate 

 to some depth into the shell of the tortoise, and finally cause it 

 to be flaked off. The Alga is reproduced by means of zoospores 

 formed in the external layer of cells. These zoospores are all 

 exactly similar, and swim about for a considerable time, after 

 which they come to rest and germinate. — On a peculiar organ 

 of Hodgsonia /icterocH/a, by Mr. Walter Gardiner. The author 

 gave some account of the gland-bearing organs which are found 

 in Hadgsonia — one in the axil of each of the foliage leaves. A 

 study of the development of these organs demonstrates that they 

 are peculiarly modified leaves, or rather bracts, since they are 

 associated with the rudimentary flower-bud. They are doubtless 

 identical with the similarly modified bracts which occur in con- 

 nection with the fully developed flowers. The glands are found 

 on the lower surface of the bract, and belong to the same type 

 as those of Luffa, although of a distinctly higher order. Glands 

 of a similar nature also occur on the under surface of the foliage 

 leaves and on tire sepals. The substance secreted by the glands 

 is most probably of the nature of nectar, and the whole struc- 

 tures are to be regarded as extra floral nectaries. Having shortly 

 described their histology, the author proceeded to make some 

 remarks upon their function. A careful survey of the various 

 gland-bearing genera of the Cucurhitacciv and PassiJlora(ci2, and 

 a comparison of such cases as those presented by Passijlora 

 qitadrangularis and Passijlora fcctida, placed it, in his opinion, 

 beyond doubt that the function of the extra floral nectaries of 

 the two orders is to attract certain insects — probably ants — 

 which are of service to the plant in protecting it from tire attacks 

 of other and harmful insects, such as caterpillars, which are 

 accustomed to creep up the narrow stem for tlie purpose of de- 

 vouring or otherwise injuring the young growing shoots. As 

 regards the fertilisation of Hodgsonia, the author showed that 

 there were special contrivances to prevent the animal which fed 

 upon the nectar of the flower from obtaining that of the extra 

 floral nectaries, and vice ve^sa, and stated that, considering all 

 the circumstances of the case, it was exceedingly probable that 

 fertilisation was accomplished through the agency of a large 

 night-flying moth. 



Edinburgh 

 Royal Society, December 20. — Sir W. Thomson, President, 

 in the chair. — The Chairman communicated a paper, by the Rev. 

 J. H. Sharpe, on a remarkable case of stream-lines in two- 

 dimensional fluid motion. The body which produces the stream- 

 lines is symmetrical about an axis, and consists of a semicircular 

 head, with another portion the form of which is given by a 

 transcendental equation. — A note on knot', by Mr. A. B. 

 Kempe, was communicated by Prof. Tait. This paper is pre- 



I 



