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January 20. — " A Study of the Thermal Properties of Methyl 

 Alcohol." By WiUiain Ramsay, Ph.D., and Sydney Young, 

 D.Sc. 



The writers have investigated the properties of the above sub- 

 stance, and obtained numerical values for the expansion of the 

 liquid, the vapour-pressure, and thecompressibility of the vapour ; 

 and from these results the densities of the saturated vapour and 

 the heats of vaporisation have been deduced. The range of 

 temperature is from - 15° to 240° C, and of pressure from 

 II mm. to 6o,ooD mm. The apparent critical temperature is 

 240°, and the pressure 59, 660 mm. The pressures were corrected 

 by means of Amagat's results, and the temperatures are those of 

 an air thermometer. 



January 27. — "On a Perspective Microscope." By G. T- 

 Biirch. 



In 1874, t'le author, while tiyingto devi';e means whereby the 

 different planes of an object shiuld be visible under the micro- 

 scope without the adjustment of the focus to each, discovered 

 that, when two lenses are separated by a distance equal to the 

 sum of their focal lengths, the optical conditions are such that 

 the magnitude of the image bears a constant ratio to that of the 

 object, no matter where upon the optic axis it is situated — the 

 ratio being that of the focal lengths of the two lenses ; that a 

 given displacciiient of the object along the axis causes a dis- 

 placement of the iamge in the same direction, but in the square 

 of the ratio. 



Further, that a picture drawn with the camera lucida under 

 these conditions has the perspective of an object magnified in 

 the square of the ratio, when it is brought within the proper 

 distance of the eye. 



The field of view of the perspective microscope is small, but 

 may be increased by using more than two lenses, and the author's 

 I'esearches gave him reason to believe that, with glasses of wide 

 angle specially constructed, a high power, with sufficiently large 

 field, might be obtained. Several uses, other than microscopic, 

 were Indicated, to which the instrument can be applied. 



The paper was accompanied by diagrams showing, in two 

 <lifirerent ways, the changes of position of the principal foci and 

 principal points, &c. , of a system of two lenses as the distance 

 between them is varied. 



A piece of moss was shown under the instrument, in magnified 

 perspective. 



" On the Thermo-dynamic Properties of Substances whose 

 Intrinsic Equation is a Linear Function of the Pressure and 

 Temperature." By Geo. Fras. Fitzgerald, F.R. S. 



Prof. Ramsay and Mr. Young have found that within wide 

 limits several substances in the liquid and gaseous stales have 

 the following relation connecting their pressure (/>), temperature 

 (T), and specific volume («>), 



/ = aT -t- <^, 

 wliere a and /' are functions of J* only. 



Now in this case the following are the forms that the thermo- 

 dynamic equations assume : T is temperature, and ip is entropy, 

 and I is the internal energy. 



Then I = 7 -I- A, 



where 7 is a function of temperature only, and A a function of 

 volume only. 



Also (p = r -f o, 



where r is a function of temperature and a of volume only. 



Also, the specific heat at a constant volume is a function of 

 the temp.rature only. 



It would be most important if by some method, Konig's for 

 instance, or by inserting a small microphone into a tube, the 

 velocity of sound in substances in various states could be accu- 

 rately determined, as that would enable us to determine 

 separately the specific heats at constant pressure and constant 

 •volume. 



Linnean Society, January 20.— W. Carruthers, F.R.S., 

 President, in the chair.— Mr. J. Benbow and Mr. F. S. J. Corn- 

 wallis weie elected Fellows of the Society.— It was announced 

 from the chair that H.R.H. the Prince of Wales had officially 

 entered his name on the roll of the Society,— The President 

 made the presentation of an oil-portrait of Francis Masson, 

 F.L.S., elected 1796.- Prof. Bayley Balfour exhibited specimens 

 and showed the microscopic structure of the "ginger-beer plant. " 

 He pointed out that, although well known and used by many 

 people as a means of manufacturing an acid drink out of sugar 

 solution and ginger, yet no scientific account of the organism 



had appeared except a short note by Worthington Smith in the 

 Girdener's Chronicle. It has the appearance of a white No toe, 

 and is composed of a Bacterium (passing through all forms of 

 rods, coils, and filaments), which apparently constitutes its 

 g.eater part ; and associated with this is a sprouting fungus. 

 Judging from descriptions and figures by Kern of the " Kephir,' 

 used in the Caucasus to induce fermentation in milk, the ginger- 

 beer plant closely resembles this ; but there are many points of 

 difference. The plant is said to have been introduced into Britain 

 by soldiers from the Crimea. — A letter was read from Mr. Bcnj. 

 l.owne referring to an exhibition by him of photographs from 

 microscopical specimens of the retina of insects. One section 

 represented the retinal layer detached from the opticon ; other 

 sections showed the basilar layer : thus practically affording 

 evidence that the nerves terminate in end organs, rods placed in 

 groups beneath the opticon — a view promulgated by Mr. Lowne 

 in his memoir published in the .Society's Transactions. — Mr. J. 

 W. Waller exhibited a block of wood, part of an oak grown in 

 Sussex containing an excavated tunnel and live larva of the 

 longicorn beetle /"riV/Kir coriiriiis. — Mr. Thiselton Dyer showed 

 and made remarl;s on two sheets of Arctic Alpine plants from 

 Corea. — Mr. F. Darwin and Miss A. Bat«on read a paper on 

 the effects of stimuli on turgescent vegetable tissues, of 

 which we hops to give an abstract in an early issue. — 

 Mr. J. R. Vaizey read a paper on the morphology ol the sporo- 

 phore in mosses. According to his researches, the seta of mosses 

 consists of an outer sclerenchyma, within which is parenchy- 

 inatous tissue, and in the middle the " central strand " ; this latter 

 being surrounded by a single layer of cells, forming the endoderm, 

 derived from the outer meristem of the growing apex. It con- 

 sists of two forms of tissue, one being of thin-walled prosenchy- 

 matous cells destitute of protoplasm, their function being to 

 conduct water: this the author \.qx\\\% proxyhm. Surrounding 

 this is a second cylinder of elongated cells with thickened walls, 

 contaming granular protoplasm ; this tissue he terms firophlocm. 

 On tracing the proxylem downwards, it is found that it gradually 

 encroaches on the other tissues by the " foot," until it takes on 

 the character of conducting tissue. The stomata on the theca 

 are confined to the hypophysis : the form of stomata in which 

 the guard-cells communicate is internally typical only of Poly- 

 trichacea: and tunaria. In the young sporagonium five distinct 

 meristems occur with difterent laws of cell-division ; one form 

 with an axial solid cylinde." he terms " endomeristem." It gives 

 rise to the central strand in the seta, and in the theca to so much 

 of the tissue of the columella as lies within the sporagenous 

 zone, the cells round this being derived from the " epomeristem," 

 whilst the sporagonium layer is itself derived fiom the endo- 

 merislem. The hypophysis is an absorbing and assimilating 

 organ, and performs all the functions of a leaf, and should be 

 classed as a phylloue. The water-conducting tissue of the 

 sporagonium only difters from the xylem of Vasculares in the 

 absence of s|>iral thickening and lignification of the cells. The 

 prophloem differs even less from the phloem of some Vasculares, 

 and though no sieve-like tubes have been made out, yet they are 

 wanting also in some Vasculares, e.g. Selaginelta. The author 

 compares the development of the sporagonmm in some respects 

 to certain parasitic plants ; and he draws the conclusion that the 

 Muscinea? are descended from an ancestor common to them and 

 Vasculars, similar to the Anthocerathea;, finally hoping in a 

 future paper to deal with their phylogeny, specially referring to 

 the vascular system and its homologue, the central strand of the 

 Musci. 



Anthropological Institute, January 25. — Anniversary 

 Meeting. — Mr. Francis Galton, F.R.S., President, in the chair. 

 — The following were elected Officers and Council for the 

 ensuing year: — President: Francis Galton, F.K.S. Vice- 

 Presidents: Hyde Clarke, J. G. Garson, M.D., Prof. A. H. 

 Keane. Secretary : F. W. Rudler. Treasurer : A. L. Lewis. 

 Council : G. M. Atkinson, Sir W. Bowman, Bart., E. W. 

 Brabrook, Sir George Campbell, M.P., C. H. E. Carmichael, 

 A. W. Franks, F.R.S., Lieut. -Colonel H. H. Godwin-Austen, 

 F.R.S., Colonel J. A. Grant, C.B., T. V. Holmes, Prof. A. 

 Macalister, F.R.S., R. Biddulph Martin, Prof. .Meld:.la, 

 F.R.S., Prof. Moseley, F.R.S., C. Peek, F. G. H. Price, 

 Charles H. Read, Lord Arthur Russell, H, Seebohm, Prof. 

 G. D. Thane, M. J. Walhouse. 



Chemical Society, December 16, 1886. — Dr. Hugo Midler, 

 F. R. S., President, in the chair. — The following were duly 

 elected Fellows of the Society : — Messrs. Horace Edward 



