NA TURE 



{Jtdy 2 1, 1 88; 



a normal condition, whether on an empty stomach, or with food, 

 or at different stages of gastric digestion, salicyluric acid was 

 found in their urine on an average three-quarters of an hour after 

 it had been taken. . From the data given above, the salol 

 must have remained one-quarter of an hour in the stomach. In 

 the case of patients suffering from gastric dilatation, the salol 

 remained much longer in the stomach. The time which 

 elapses between the administration of salol and the appearance 

 of salicyluric acid in the urine may hence be used as an important 

 means of diagnosing cases of slight gastric dilatation. After pro- 

 longed electrical stimulation of the abdominal muscles, the 

 passage of salol into the intestine was quickened. — Prof. Zuntz 

 criticised a theory of the excretion of carbonic acid in the pul- 

 monary alveoli which has been put forward by von Fleischl, ac- 

 cording to which the shock given to the blood by the contraction 

 of the heart is to be regarded as the chief cause of the diffusion 

 of the carbonic acid through the alveolar walls. The speaker 

 refuted this theory as being both unproved and unnecessary. 

 — Dr. Goldschneider communicated the results of his experi- 

 ments on the reaction-time of the perception of temperature. It 

 has been known for a long time that cold is more quickly per- 

 ceived than heat. As a starting-point, the speaker had first 

 carried out some direct measurements. He sought out portions 

 of the surface of the body which were equally sensitive to heat 

 and cold ; these parts were then stimulated as far as possible 

 with equal intensity, and the results were as follows, taken 

 as a mean of about two thousand separate measurements : — 

 The reaction-time for cold as a stimulus is for the face 13 "5, 

 for the arm 18, for the abdomen 22, and for the knee 25 

 hundredths of a second. When an equally strong heat stimulus 

 was applied, the numbers obtained were 19, 27, 62, and 79 

 hundredths of a second. The ratio of the reaction-times was 

 found to be about the same when the stimuli were applied to 

 such a nerve as the trigeminal which goes straight to the brain 

 and to a spinal nerve. The experiments on thermal stimulation 

 were made by bringing a metallic button in contact with the 

 skin and recording electrically the moment of contact ; the 

 resulting sensation was indicated by a Beiss key. The degree 

 of heat and cold employed as a stimulus was selected so as to 

 differ by equal amounts from the temperature of the skin. 

 From the results of the experiments. Dr. Goldschneider deduced 

 some theoretical conclusions as to the nature of our sensations 

 of heat and cold. 



Physical Society, June 27. — Prof, von Helmholtz, President, 

 in the chair. — Prof, von Bezold demonstrated the currents, which 

 he has very fully investigated, which occur in a fluid as the result 

 of varying temperatures or the rotation of the vessel in which 

 the fluid is contained. These currents were made visible, as 

 they occur in a large mass of water, by means of a few drops of 

 hectograph ink, which at first spreads itself out in radiating 

 lines over the surface, then sinks in the form of threads and 

 columns, and, following the direction of the currents in the 

 fluid, presents an extremely interesting appearance of rotatory 

 formations. — Dr. Richarz has closely studied what takes place 

 in an electrolyzing cell during the decomposition of water in the 

 immediate neighbourhood of the electrodes daring the passage 

 of the currents of electrolytic convection. As is well known, 

 an electromotive force of i -5 Daniell is necessary in order that 

 the current may pass electrolytically and the water be decom- 

 posed ; if the electromotive force is less than the above, the 

 water is not decomposed, but at the same time it can be shown 

 that the electricity does traverse the fluid. According to Von 

 Helmholtz's views on electrolysis, when the electromotive force 

 is small, currents of electrolytic convection pass through the 

 fluid, which are kept up by the occlusion of the positively 

 charged hydrogen atoms at the kathode and by the neutral 

 oxygen in solution. Starting from the work of Moritz Traube, 

 who has proved the formation of hydrogen peroxide at the 

 kathode in the electrolyzing cell, Dr. Richarz has been able to 

 prove, both qualitatively and quantitatively, the formation of 

 hydrogen peroxide at the kathode during the passage of con- 

 vection currents. This formation of the peroxide takes place, 

 according to the views of the speaker, by the union of two atoms 

 of the occluded hydrogen with the neutral molecule of the dis- 

 solved oxygen, which has given up its positive charge to the 

 kathode. As the result of this separation of the occluded hydro- 

 gen, fresh portions of hydrogen can be occluded by the metal of 

 the electrode, and in this way a renewal of the electric current 

 can take place. — Prof. Neesen described a vapour-calorimeter, 

 consisting of a glass vessel into the centre of which projects a 



glass tube, closed at the lower end, for the reception of the 

 substance under investigation. This tube is surrounded with a 

 mass of lamp- wick, which is saturated with ether, and dips into 

 a small quantity of liquid ether in the bottom of the outer 

 vessel. Another glass vessel, exactly similar to the above, is 

 joined to it by means of a capillary U-tube, in which a small 

 drop of ether serves as an index. When a warm substance is 

 dropped into the calorimeter, an amount of ether is converted 

 into vapour proportional to the heat given up, and the volume 

 of this vapour, as measured by the displacement of the ether 

 index, gives the heat yielded by the substance. Prof Neesen 

 is still engaged in testing and improving the calorimeter, and 

 only made the above preliminary communication as this was 

 the last meeting of the Society before the summer vacation. — 

 Dr. Grunmach exhibited a double quartz plate, which was not 

 made of a right- and left-handed quartz plate, but was cut from 

 a twin crystal, in which the fusion of the two crystals is so per- 

 fect that every slice cut from this twin crystal may be used as a 

 double plate in the polarizing apparatus. 



BOOKS, PAMPHLETS, and SERIALS RECEIVED. 



Walks in the Ardennes : J. W. Richards (Low). —Welsh Question and 

 Druidism, Third Edition : Griffith (R. Banks). — Annual Report of the 

 Department of Revenue, Settlement, and Agriculture, for 1885-86 (Madras). 

 — Journal of the Royal Statistical Society, June (Stanford). — Journal of 

 Physiology, vol. viii. No. 2 (Cambridge). — The Indian Forester, vols, ii., iv., 

 vi., vii., viii. (Calcutta). — Annalen der Physik und Chemie, 1887, No. 8^ 

 (Leipzig). — Museum d'Histoire Naturelle des Pays-Bas, tome ix. Catalogue 

 Ostiologique des Mammiferes ; F. A. Jentink (Brill, Leide). 



CONTENTS. PAGE 



The Mining Industry of New Zealand 265 



A Century of Electricity 266 



Our Book Shelf :— 



Pratten :" My Himdred Swiss Flowers " 266 



Hay: "The Fungus Hunter's Guide and Field 



Memorandum Book " 267 



Letters to the Editor : — 



TheCarnatic Rainfall. — General Richard Strachey, 



F.R.S 267 



Is Cold the Cause of Anticyclones? — H. Helm 



Clayton 268 



Physiological Selection. — H. K. Rusden 268 



Weight, Mass, and Force.— Prof. A. G, Greenhill . 269 

 The Sky-coloured Clouds.— T. W. Backhouse . . 269 

 The Migrations of Pre-Glacial Man.— Dr. Henry 



Hicks, F.R.S 269 



Abstract of the Results of the Investigation of the 

 Charleston Earthquake, I. By C. E. Button, 

 U.S.A., and Everett Hayden, U.S.N., U.S. 



Geological Survey. ( With a Map) 269 



Experiments on the Sense of Smell in Dogs. By 



Dr. George J. Romanes, F.R.S 273 



Fossil Wood from the Western Territories of 

 Canada. By Sir J. William Dawson, C.M.G., 



F.R.S 274 



The Liverpool Marine Biology Station on Puffin 

 Island. By Prof. W. A. Herdman. ^^Illustrated) . 275 \ 



Antarctic Exploration 277 



The Captive Kite-Balloon. By E. Douglas Archibald. 



{Illustrated) 278 



Notes 27c 



Our Astronomical Column : — 



The Nice Observatory 28: 



Astronomical Phenomena for the Week 1887 



July 24-30 28; 



Geographical Notes 28. | 



The Technical Education Bill 28.! 



Scientific Serials 28 



Societies and Academies 28 



Books, Pamphlets, and Serials Received 28 



