January 3, 1895] 



NATURE 



239 



animal from the conrlition of chloroform collapse. That these 

 results agree entirely with McWilliams', and are opposed to 

 tliose of the Hyderabad Commission. 



(21) That the feet-down poiition inhibits respiration, and the 

 fecl-up position accelerates it. 



(22) That these respiratory results probably depend upon the 

 stimulation of sensory nerve endings by changes of tension 

 lirought about by the .alterations of position, because the results 

 are abolished by dividing the vagi. 



(23) That in the feet-down position the respiration is 

 thoracic in type, and the abdomen is retracted ; in the feet-up 

 position the respiration is diaphragmatic and the abdomen freely 

 expanded. 



(24) That these types of respiration tend to compensate for 

 the effects of gravity on the circulation, for the retraction of the 

 abdomen in the feel-down position mechanically supports the 

 abdominal veins, whilst the thoracic inspiraiions aspirate blood 

 into the heart. In the feet-up position the full and free expansion 

 nf the abdomen withdraws all obstacles to the compensatory 

 liilatation of the abdominal veins. 



In the last part of ihe paper the medical aspects of this 

 ri:iearch ate discussed. It is suggested that emotional syncope 

 i> due to paralysis of the splanchnic area, and a case is quoted 

 uliere compression of the abdomen immediately removed the 

 syncopal condition. The same treatment, or that of elevation 

 1.1 the abdomen, is suggested for conditions of shock, chloroform 

 cdlapse, and after severe haemorrhage. 



linally, a parallel is drawn between some of the results of 

 this research in reference to monkeys and those obtained by 

 In. George Oliver on man, by measuring the diameter of the 

 r.vlial artery with his ingenious instrument, the arteriometer. 



Physical Society, December 14, 1894. — Prof. W. E. 

 .■\yrton and Mr, II. C. Haycraft communicated a paper on a 

 studenls' simple apparatus for determining the mechanical 

 livalenl of heat. lilr. Haycraft, who read the paper, explained 

 ii the object at which the authors had aimed was the construe- 

 .. jii of an apparatus which could be placed inthe hands of junior 

 students, and by means of which a result correct within one per 

 cent, could be obtained, without the introduction of troublesome 

 corrections. The method employed is the electrical one, and 

 the measurements to be made are (l) the value of the constant 

 current passed through the resistance, as given by a direct-read- 

 ini; ammeter ; (2) the average value of the P. t). between the 

 terininals of the resistance, as given by a direct-reading volt- 

 meter ; (3) Ihe mass of water heated //;« the water-equivalent of 

 the containing vessel, resistance-coil, and stirrer ; (4) the rise of 

 temperature of the water ; (5) the time during which the current 

 is passed. Of these the measurements (i) (2) (3) can be effected 

 without the introduction of an error anything like as great as one 

 percent. The ca^e of (4) and (5) is different. The riseof tem- 

 |ierature, to be measured with accuracy, should be fairly consider- 

 able, a:id the same remark applies to the time of heating as 

 measured by an ordinary stop-watch. At the same time, if 

 these two quantities are made unduly great, there will be too 

 meat a ratio of heat lost to heat generated during the experi- 

 ment. The authors consider that, with a given amount of elec- 

 trieal power available, the best conditions will be obtained by 

 making the percentage accuracy of the temperature measurement, 

 tlie[>ercrntage accuracy of the lime measurement, and thepercent- 

 a:.;e of generated heat lost by surface cooling equal. Hence they 

 determine ihe mass of water to be used and the time of heating 

 which may be expected to give the best results. I he immersed 

 conductor is a strip of manganin about 0*25 inch wide, 003 inch 

 thick, and 5 feet long, which is bent into a series of zig-zags, 

 so as to I iin a kind of circular gridiron, the successive portions 

 of strip lyng all in one plane, and the whole being held rigid 

 by a SI rip of vulcanised fibre, to which each portion of the 

 strip is screwed. Another precisely similar grid is placed 

 3 inches below the first, and the two are joined in series, and 

 are mechanically connected together by thin vulcanite pillars. 

 The water is contained in a glass beaker of just sufficient 

 diameter 10 lake the framework of manganin strip. This latter 

 exposes a considerable surface (about 400 sq. cm.) to the water, 

 and is moved bodily up and down during the experiment, thus 

 constitu ing an efficient stirrer. To allow sufficient freedom of 

 movement, electrical connection is made by means of very 

 flexible leads, each made up ol about 210 thin copper wires. 

 The results obtained by .students for the heat equivalent of the 

 J watt-second have an average deviation from the mean, if several 

 1 experiments are made, of less than one-half per cent. ; and 

 Ihey agree with the best standard determinations within one 



NvJ. 1314, VOL. 51] 



per cent. Mr. Griffiths thought it inadvisable to provide junior 

 students with apparatus from which every source of error had 

 been eliminated ; they were thus led to underrate the difficulty 

 of an experiment, and the care required to obtain reasonable 

 accuracy. Prof. Carey Foster agreed, generally, with Mr. 

 Griffi;hs, and deprecated the use of direct-reading ammeters 

 and voltmeters in experiments of this kind. He thought it 

 preferable that a student should learn to reduce instrumental 

 readings to absolute measure fir himself. Prof. S. P. Thomp- 

 son dissented from the opinions expressed by the two previous 

 speakers, and thought it was an advantage to students to have 

 the use of direct reading instruments. Dr. Sumpner described 

 a simple method which he had employed for measuring the 

 mechanical equivalent of heat, and which depended on the 

 heating of a stream of water, as it flowed through a pipe con- 

 taining the current-conductor. Prof Riicker was inclined to 

 take an intermediate view of the questions that had been rai-ed. 

 He thought that students should take for granted as little as 

 possible concerning their instruments; but to verify every 

 point, even if practicable, would occupy a great deal of time 

 which might otherwise be more profitably employed. Prof. 

 Ayrton replied, and explained that the calibration of 

 ammeters and voltmeters would be part of the work 

 of a student at another pait of his course. — A paper 

 by Prof. Ayrton and Mr. E. A. Medley, entitled "Tests 

 of glow-lamps, and description of the measuring instru- 

 ments employed," was commenced by Mr. Medley, ihe latter 

 pan of the paper being held over till next meeting. The object 

 of the investigation was to find at what E. M.F. glow-lamps 

 could be most economically run. Too low an E. M.F. gives a 

 low efficiency, and too high an E. M.F. renders the lamps 

 short-lived ; so that there must be (for a given lamp) a certain 

 E.M.F. which is more economical 10 work at than any other. 

 It was also pointed out that, as glo.v lamps deteriorate and 

 become less efficient with use, it may be an economy to discard 

 a lamp before the filament actually breaks. The lamp is then 

 said to have reached the "smashing point." Accumulators 

 were used to drive the lamps, automatic apparatus being used 

 to keep the E.M.F. constant, and when a lamp filament Broke, 

 the (act was automatically recorded on a tell-tale. 



Geological Society, December 19, 1S94 —Dr. Henry- 

 Woodward, F.R.S., President, in the chair. — The Lower 

 Greensand above the Athei field Clay of East Surrey, by 

 Thomas Leighton. This paper embodies the results of the 

 author's examination of the Lower Greensand of East Surrey 

 during the thcee years 1892-94. The area discussed in 

 the paper extends from Leiih Hill in the west to Tilburstow 

 Hill in the east; and the divisions of the Lower Greensand 

 chiefly referred to are those hiiheito known as the Bargate, 

 San.lgate, and Hythe beds. The author stated that the Lower 

 Greensand of East Surrey sho.vs that formation to consist of 

 beds de^iosited in a marine estuary or narrow sea, not far from 

 land and within the influence of strong currents, extending 

 geneially from N.W. to S.E., so that, without palxontological 

 evidence, no correlation of beds here wiih those exposed at 

 .Sandgate and at Hythe is possible. He arrived at this con- 

 clusion by following the outcrop of the various chert-beds, 

 which, alier Dr. G. J. Hinde [Phil. Trans. Koy. Sac. vol. 

 clxxvi. 1SS5), are accejited as of sponge origin (deep-water 

 deposits), and further by following the outcrop of the pebble- 

 beds, described by Mr. C. J. A. Meyer (GVo/. A/a«: for 1S66, 

 p. 15). — On the eastern limns of the Yorkshire and Derbyshire 

 or Midland coalfield, by W. S. Gresley. The author attempted 

 to throw light on the question of the easterly extension of the 

 Yorkshire, Derbyshire, and Nottinghamshire coalfield beneath 

 the newer rocks. He noticed the general trend i^f the strata, 

 the sizes of other British coalfields, the question of the origin 

 of mountains, straiigraphical considerations, and the faults of 

 ihe North ol England. — On some phases of the structure and 

 peculiarities of the 'iron ores of the Lake Superior region, by 

 \V. S. Gresley. The autbor has studied heaps of ore brought 

 from the region lying south-west of Lake Superior since 1S90. 

 He described certain structural features of the ore-lragments, 

 and discussed the evidences of mechanical movements and 

 chemical alteration exhibited by these fragments. 



Chemical Society, December 6, 1894. — Dr. Armstrong, 

 President, in the chair. — The relative behaviour of chemically 

 prepared and of atmospheric nitrogen in the liquid state, by 

 James Dewar, F.R.S. — On the use of the globe in the study 

 of crystallography, by J. Y. Buchanan, F.K.S. — A new 

 method of obtaining dihydroxytartaric acid, and the use of 



