238 



NA TURE 



[January 6, 1898 



the continuity of the jet. He finds that air or oxygen ha%-e 

 no effect when quite dry. — Temperature of the electrodes of 

 mercury arc lamps, by L. Arons. In the arc lamp with 

 mercury electrodes, devised by Arons, the anode is the hotter, 

 and gradually distils over into the kathode, which is flickering 

 and turbulent. Mercury is condensed on the walls of the 

 vacuum tube, which are easily obscured. — Deflection of kathode 

 rays, by W. Kaufmann and E. Aschkinass. The authors deter- 

 mined the deflection produced in kathode rays by a narrow 

 field due to condenser plates mounted in a tube crossing the 

 vacuum tube at right angles. They found that the amount of 

 deflection observed is strictly in accordance with the projection 

 hypothesis of kathode rays as against the German wave hypo- 

 thesis. — Magnetic deflection of kathode rays, by W. Kaufmann. 

 The above result led the author to redetermine the ratio ejiii 

 of the charge of the projected particles to its mass, by a close 

 study of the magnetic field deflecting the ray. It was found to 

 be 177 X 10'' instead of lo^ — Kathode rays, by E. Wiedemann 

 and G. C. Schmidt. There are two distinct kinds of kathode 

 rays, which proceed from a point in the form of a solid cone 

 and of a hollow cone respectively, producing on the wall of the 

 tube a patch or a ring. The authors studied these two species 

 under the simplest conditions. They placed a knob, forming 

 the terminal of a Lecher secondary wire, against an exhausted 

 glass sphere without electrodes. A hollow cone proceeded 

 from a point in the sphere next to the knob, whose angle varied 

 with the exhaustion, the size of the sphere, and the curvature 

 of the electrode, increasing as they increased. — Electric observa- 

 tions by balloon, by R. Bornstein. The balloon offers the best 

 means of determining the true potential at any point in the 

 atmosphere, but the charge of the balloon itself is a source of 

 error. This may be eliminated by employing three collectors 

 for three successive points below the balloon, and only about 

 2 m. distant from each other. If the decrease of potential is 

 uniform, the charge of the balloon is zero. Otherwise, the 

 charge is easily calculated from the observed decrements. — 

 Thermodynamics of luminescence, by K. Wesendonck. A 

 luminescent body is capable of imparting heat to a body warmer 

 than itself. This does not contradict the second law of thermo- 

 dynamics, as luminescence is not ordinary thermal radiation. 



SOCIETIES AND ACADEMIES. 

 London. 



Royal Society, December i6, 1897. — " The Comparative 

 Chemistry of the Suprarenal Capsules." By B. Moore, M.A., 

 and Swale Vincent, M.B. 



In this paper it is shown that the " paired bodies" of Elasmo- 

 branch fishes contain the same chromogen as the medulla of the 

 suprarenal capsules of mammals. In previous papers Vincent 

 had shown not only that the " paired bodies " bear a close 

 resemblance histologically to mammalian medulla, but that they 

 contain a substance which constricts arterioles and raises blood 

 pressure in a similar manner to mammalian medulla. 



From the chemical point of view Moore had further shown 

 that this active substance is closely associated with a chromogen 

 also found only in the suprarenal medulla. The active material 

 and chromogen are not, however, identical, for the activity may 

 be destroyed without destroying the chromogen by allowing the 

 material to stand for seven to ten days in strong alcohol. 

 Moore hence supposes that the active material has a complex 

 molecule which is decomposed by the alcohol, and that the 

 chromogenic properties are attached to a group in this molecule 

 which is unattacked in the decomposition. ~, 



The colour reactions of the chromogen show that it contains 

 an ortho-dihydroxy-benzene nucleus ; thus, it gives a deep green 

 coloration with ferric chloride, and reduces silver nitrate in the 

 cold. Besides these tests, it gives a rose-red colour with 

 alkalis and free halogens and other reactions, which show that 

 it is a strong reducing agent. 



Using these colour reactions as tests the chromogen was 

 sought for in extracts of the paired bodies of Elasmobranchs 

 (Scyiliti/n canicula), and was found to be present in abundance. 



It was also shown, that no chromogen is present in the 

 interrenal of Elasmobranchs, which, according to Vincent, 

 corresponds to the cortex of the suprarenal of mammals. 



Thus, additional evidence is furnished that the paired bodies 

 correspond to mammalian medulla, while the inter-renal does not 

 resemble medulla and is probably cortex, as suggested by 

 Vincent. 



NO. T471, VOL. 57] 



" On a Method of determining the Reactions at the Points 

 of Support of Continuous Beams." By George Wilson, M.Sc, 

 Demonstrator in Engineering in the Whitworth Laboratory of 

 the Owens College, Manchester. 



The solution given in this paper differs from those of Bresse, 

 Clapeyron, and Heppel, insomuch that the reactions at the 

 points of support are considered as the unknown quantities to 

 be determined, instead of the bending moments over the piers. 



It is shown that by considering the continuous beam as a 

 beam supported at each end and under the action of the given 

 loading acting downwards, and the intermediate supports con- 

 sidered as unknown concentrated loads acting upwards, and 

 equating the deflection at any intermediate point of support 

 caused by the former loading to that caused by the several 

 intermediate reactions treated as concentrated loads, the 

 following series ot equations is obtained, viz. : — 



Nj = Ri«i' -f RjWi" + Rj"/" -h . . . 



N.^ = Ri«j' -f R2W2" + Rs"/' + . . . 



&c. &c. 



Where R with the correct suffix is the reaction at any inter- 

 mediate point of support, and N and n with their suffixes are 

 quantities depending on the dimensions of the beam and the 

 loading. 



The quantities w are constant and need only be determined 

 once, whilst the value of N changes with the position and 

 magnitude of the live load. A method of determining these 

 constants when the cross section of the beam is variable, is 

 given ; when the cross section is uniform, the equations can be 

 written down at once. 



The elevation or depression of the supports from any cause 

 affects the values of R, the alterations in which can be deter- 

 mined by means of the above equations when the amount of 

 the elevation or depression is known. 



An example is appended to show the application of the 

 method. 



Geological Society, December 15, 1897.— Dr. Henry Hicks, 

 F. R. S., President, in the chair. — On the Pyromerides of Boulay 

 Bay, Jersey, by John Parkinson. After briefly noticing the 

 literature of the subject, the author described the altered 

 rhyolites of Boulay Bay. One variety, the commonest, is of a 

 dark red colour, showing flow-structure ; another is porphyritic ; 

 a third, near the centre of the Bay, has a pale greenish matrix 

 enclosing fragments, which, however, are due to flow-breccia- 

 tion. Large pyromerides occur in two localities : in the more 

 interesting, that north of the jetty, the structure of the rock 

 indicates either a very peculiar magmatic differentiation in silu 

 or (more probably) the mixture of two magmas differing in their 

 stage of consolidation. From study of a series of specimens of 

 the pyromeridal rock, the author arrived at the following con- 

 clusions : (i) The rock shows marked flow-structure and at 

 times bands which indicate a slight difference in its compositi(jn, 

 the latter tending to as.sume a moniliform outline. In such the 

 microscopic structure corresponds with that of the pyromerides, 

 and exhibits traces of radial crystallisation. (2) These afford a ,-., 

 passage into somewhat oval pyromerides, with rather tapering ^' 

 ends and irregularly mammillated surfaces. (3) From these 

 sometimes a single one seems to be thrown oft, while lines of 

 pyromerides or little lumps of similar material are scattered 

 about the matrix. (4) Many of the pyromerides are solid 

 throughout ; others have a central cavity filled with quartz. — 

 On the exploration of Ty Newydd Cave near Tremeirchion, 

 North Wales, by the Rev. G. C. H. Pollen. In November 

 1896 a Committee was formed, consisting of Dr. H. Hicks, Dr. 

 H. Woodward, and the author, for the purpose of exploring 

 this cavern, which is situated in the same ravine on the east side 

 of the Vale of Clwyd as the well-known caverns of Ffynnon 

 Beuno and Cae Gwyn, explored about twelve years ago by Dr. 

 H. Hicks and Mr. E. B. Luxmoore. Grants have been made 

 by the Royal Society and by the Government Grant Committee 

 for the purpose of carrying on the explorations ; and though a 

 considerable time must elapse before the work is completed, the 

 results already obtained are of importance. The cavern had 

 been in part broken into by quarrying operations, but the 

 chambers and tunnels were completely filled up with more or 

 less stratified deposits, and had remained entirely untouched. 

 Although the ground above the cavern is strewn over with drift 

 and erratics from the north and from the central areas of Wales, 

 not a fragment of anything but immediately local material has 



