ii8 



NATURE 



[June 3, 1897 



" The University College of Sheffield," and that women may 

 participate in the benefits, emoluments, and government of the 

 College to such an extent and in such a manner as the statutes 

 of the College shall prescribe. There is to be no religious test 

 for students, teachers, or other officers. The first president is 

 the Duke of Norfolk, who is to hold office for five years, and be 

 eligible for re-election. The first vice-presidents are Sir F. T. 

 Mappin, Sir Henry Stephenson, Dr. H. C. Sorby, and Dr. 

 Dyson. 



SOCIETIES AND ACADEMIES. 



London. 



Royal Society, May 13. — "On a New Method of Determin- 



ing the Vapour Pressures of Solutions." By E. B. H. Wade, 

 B.A., Scholar and Coutts Trotter Student of Trinity College, 

 Cambridge. Received April 26. 



The statical methods, which have hitherto alone been capable 

 of furnishing results between 60° C. and 100° C. , have been at- 

 tended with serious errors. The apparatus employed in this 

 research was in conception similar to that of Sakurai, except that 

 it was in duplicate, a divided steam supply passing through two 

 U-tubes placed in parallel. It differed, however, from his 

 apparatus in several important particulars, which cannot be 

 adequately described in a brief notice. 



Suffice it to say, that the pressure on the contents of the two 

 U-tubes being the same, could be adjusted to any convenient 

 value, and that the method of thermometry being the differential 

 platinum one, the difference only of the boiling-points of pure 

 water and salt solution, in their respective U-tubes, was recorded. 

 Two series of observations were made at a pressure of 760 mm., 

 in one of which a small external heat supply was used to com- 

 pensate the condensation in the U-tubes, and a second in which 

 it was found possible to dispense with it. 



Neither method gives results differing systematically from the 

 other, though the latter method was greatly preferred. 



The substances examined were the chlorides of lithium, 

 calcium, strontium, sodium, and potassium, and bromides of the 

 two last named. A full discussion is here impossible, but we 

 may notice that in all cases the ratio increase of boiling-point 

 to concentration is of the same order as that calculated from 

 Arrhenius' theory, but that the discrepancy always exceeds the 

 experimental error, except in the case of potassium chloride, and 

 is particularly great in the case of calcium chloride. The latter 

 substance gave less well-defined boiling-points than the others 

 which were investigated, for some reason as yet unknown, and 

 the experimental error was here certainly at its greatest, but still 

 not nearly enough to account for the difference. 



May 14. — "An Attempt to cause Helium or Argon to 

 pass through Red-hot Palladium, Platinum, or Iron." By 

 William Ramsay, F.R.S., and Morris W. Travers. Received 

 April 9. 



A tube of hard, infusible glass was connected at one end with 

 the reservoir of the gas under experiment, helium or argon. 

 Into its other end was corked a tube of platinum, closed with a 

 palladium cap, or, if iron was the metal under experiment, with 

 a tube of thin wrought iron, also closed at the end ; the closed 

 end of the interior tube was placed so that it could be raised to 

 a bright red heat by bringing a blow-pipe flame to bear on the 

 hard glass tube. The open end of the metal tube was cemented 

 to a glass tube, attached to a Topler's pump, and provided with 

 a Plucker's vacuum tube, so that the spectrum of any gas passing 

 through the metal could be observed. This afforded, at the 

 same time, a most delicate test of the presence of the gas under 

 experiment. The metal tube was exhausted, until green phos- 

 phorescence appeared in the vacuum tube, and the gas, helium 

 or argon, was admitted into the space between the glass and the 

 metal tube, at atmospheric pressure. The glass tube was then 

 heaed to the highest temperature attainable with a blow-pipe— 

 peihaps 900° or 950° C. In no case, whether the metal tube 

 consisted of palladium, platinum, or iron, was there the smallest 

 transpiration of gas, even after half an hour. The phosphor- 

 escent vacuum remained in all experiments quite unimpaired. 



Physical Society, May 28.— Mr. Shelford Bidwell, Presi- 

 dent, in the chair. — Mr. Elder read a paper, communicated by 

 Dr. Albert A. Gray, on the perception of the difference of phase 

 by the two ears. The investigation relates to certain acoustical 

 results obtained some years ago by Dr. S. P. Thompson ; they 

 may be summarised as follows : {a) When two simple tones in 



NO. 1440, VOL. 56] 



opposite phases are conveyed separately, through tubes or other- 

 wise, to the two ears, the sensation of sound appears localised at 

 the back of the head, (^b) If the respective tones from two 

 forks mistuned to give " beats" are conducted separately to the 

 two ears, they still produce the sensation of " beats" ; and, to 

 the observer, this sensation also seems localised at the back of 

 the head. The "beats" are distinct, but there are no true 

 silences, at any rate so long as attention is fixed on the note. 

 [c) Although "beats" are heard under these circumstances, no 

 beat-tones are discernible by the binaural method. The author 

 proceeds to explain the phenomena on the assumption that there 

 is a physiological connection between the nerves of both ears. 

 His evidence is derived from the following experiments : (</) A 

 vibrating fork is held opposite one ear ; the opposite ear is then 

 closed by a finger ; the sound of the fork now appears louder to 

 the open ear. {e) If the fork is held opposite one ear, and the 

 chain of ossicles of the second ear is then pressed gently in- 

 wards by a fine probe, the sound of the fork is heard with in- 

 creased loudness by the first ear. (/) If the chain of ossicles in 

 the second ear is dragged outwards by rarefaction of the air in 

 the meatus, the above changes in loudness are no longer per- 

 ceptible. The theory put forward by the author in explanation 

 of these results is that they are due to reflex contractions of the 

 tensor tympani or stapius (or more probably both) of the first 

 ear. A further observation, of Pollak, is also brought to bear 

 upon the question, i.e. {g) stimulation of one cochlea by sound 

 causes contraction of the tensor tympani of both ears, and the 

 contraction is permanent while the sound continues. This is known 

 to be true for the lower animals, and is probably true for man. 

 With regard to {a), the author observes that the muscular sense 

 is there being appealed to in a manner quite new to it. The 

 tympani are by nature trained each to relax or expand with the 

 other, and they are thrown out of reckoning if the phases differ. 

 Or, again, the stimuli from the two ears may collide at one of the 

 lower nerve centres, and thus be annulled before any intimation 

 has been received by the brain. The path taken by such stimuli 

 is from the nucleus of one nerve, just after its entrance into the 

 medulla, across to the corresponding nucleus of the opposite 

 side. In these nuclei the stimuli from both ears mix. Some of 

 the nerve-fibres have no nuclear intercommunication at the base 

 of the brain ; consequently, stimuli passing by these paths are 

 not subject to interference. This agrees with (b), where the 

 silences are not complete, [h) It is to be observed that beat- 

 tones are sometimes perceived by the ear under circumstances 

 where they cannot set a resonator into vibration. This indicates 

 that beat-tones may be produced either in the ear or nerve-centres 

 of the listener, and not exteriorly. (/) It has been shown by Dr. 

 Thompson that when two simple tones, such as in ordinary hearing 

 produce a differential tone, are led singly to the ears, no differential 

 tone is heard. From this the author concludes that differential 

 tones are not produced in the mind of the listener, nor in any of 

 the cerebral centres. From [h) and (?) together, the point of pro- 

 duction is restricted down to the ear itself; something of the 

 sort was suggested by Helmholtz. Again, from [g), it appears 

 that when two notes are sounded so as to give a differential 

 tone, the tensor tympani must be in a state of continual con- 

 traction, for the intervals of silence are too short to permit of 

 any relaxation. Meanwhile, there are certain periods during 

 which the tympani membranes are not acted upon by any force 

 external to the ear. The author is of opinion that if the move- 

 ments of the ossicles upon one another were absolutely friction- 

 less the membranes would come to rest in a position where 

 the force of the contracting muscle was balanced simply by 

 the tension of the membrane and the ligaments of the 

 ossicles ; but since the articulations of the ossicles have some 

 friction, the equilibrium is otherwise, and he conjectures that the 

 state of affairs is such that any force acting upon the hammer, 

 tending to draw it inwards, produces a slight jerk, and this 

 repeated gives the necessary impulses for the sensation of 

 differential tones. The mechanics of this theory is not fully 

 worked out. — Mr. J. Rose-Innes read a paper on the isother- 

 mals of isopentane. The author takes advantage of the recent 

 experimental work of Ramsay and Young, upon the thermal 

 properties of isopentane, to test a formula giving the relation 

 of pressure to temperature for gases generally, over a consider- 



able range of volume. From the linear equation, p = bT -a, 

 for the pressure at constant volume, where a and b are functions j 

 of the volume, no formula could be found to give close agree- j 

 ment with observed results. More definite results are obtained | 

 by examining a quantity depending upon a and b together ; 



