ASSOCIATIONS FOR THE ADVANCEMENT OK S( IKNCE. (BRITISH.) 



33 



ganisms with external influences was indicated 

 l-y illustrations of phototaxis, or the influence of 

 li'k'lit in diiecting the movements of free-moving 

 cells. Similarly the action of chemistaxis, or 

 the movements of anthcrozoids of ferns and 

 m.i--fs guided by impressions derived from 

 chemical sources, as by the allurement of certain 

 chemical substances (sugar, etc.) in solution, was 

 <li>cussed. In conclusion he said: 



" The purpose which I have had in view has 

 been to show that there is one principle that 

 of adaptation which separates biology from 

 the exact sciences, and that in the vast field of 

 biological inquiry the end we. have is not merely, 

 as in natural philosophy, to investigate the rela- 

 tion between a phenomenon and the antecedent 

 inn! concomitant conditions on which it de- 

 pends, but to possess this knowledge in constant 

 reference to the interest of the organism. What 

 I have desired to insist on is that organism is a 

 fact which encounters the biologist at every step 

 in his investigations : that in referring it to any 

 general biological principle, such as adaptation, 

 we are only referring it to itself, not explaining 

 it ; that no explanation will be attainable until 

 the conditions of its coming into existence can 

 be subjected to experimental investigation so as 

 to correlate them with those of processes in the 

 nonliving world." 



A. Mathematics and Physics. The presiding 

 officer of this section was R. T. Glazebrook, 

 P. R. S., who, in opening, expressed his regret at 

 the inability of Prof. Clifton to fill the pTace of 

 president of the section, which nomination he 

 had accepted from the council. A brief retro- 

 spect of the prominent events in the sciences per- 

 taining to the section that had occurred during 

 the year followed, including mention of Bar- 

 nard s discovery of the fifth satellite of Jupiter 

 at the Lick Observatory. The electrical stand- 

 ards proposed at Edinburgh had been accepted 

 by France, Germany, Austria, and Italy, and had 

 been ratified by the congress held in Chicago. 

 Griffith's redetermination of the mechanical 

 equivalent of heat and Rowland's table of stand- 

 ard wave length were among the investigations 

 completed. Lord Rayleigh s work on the in- 

 tensity of light reflected from water and mer- 

 cury at nearly perpendicular incidence, Dewar's 

 experiments on the liquefaction of oxygen and 

 nitrogen on a large scale, were referred to. 



Mr. Glazebrook then took up the more special 

 subject of his address and discussed the various 

 optical theories. Starting with the statement 

 that " light is propagated by an undulatory mo- 

 tion through a medium which we call the ether 

 is now an established fact," he discussed the 

 emission theory advanced by Descartes, and the 

 undulatory theory of Hooke; then, passing to the 

 treatment of the subject by Newton, he led the 

 way down through the researches and opinions 

 of Huygens, Young, and Fresnel to the more re- 

 cent writings of Navier, Poisson, and Cauchy. 

 Finally he took up the views of Lord Kelvin, 

 and spoke of the application of electricity to ex- 

 plain the theory. 



" Still such a theory is not mechanical, as we 

 have no satisfactory mechanical theory of the 

 electro-magnetic field. But the theory of the 

 quasi labile ether may be applied, and gives two 

 analogies according as we regard the density of 

 VOL. xxxin. 3 A 



the medium to be analogous to electrostatic in- 

 ductive capacity or to magnetic pcrmruhility. 

 The former gives results consistent with Max- 

 well's equations for the electric stresses, but i 

 more difficult to grasp. According to these 

 analogies an electrified conducting sphere is not 

 a body charged with a quantity of something we 

 call electricity, but a surface at which there is a 

 discontinuity in the rotation impressed upon the 

 medium or in the flow across the surface, for 

 in the conductor a viscous resistance to the mo- 

 tion takes the place of rigidity. No permanent 

 strain can be set up. From this standpoint we 

 consider electrical force as one of the manifesta- 

 tions of some action between ether and matter. 

 There are certain means by which we can strain 

 the ether ; the friction of two dissimilar mate- 

 rials, the chemical action in a cell are two ; and 

 when, adopting this second analogy, this strain- 

 ing is of such a nature as to produce a rotational 

 twist in the ether, the bodies round are said to 

 be electrified ; the energy of the system is that 

 which would arise from the presence over their 

 surfaces of attracting and repelling matter, at 

 tracting or repelling according to the inverse 

 square law. We falsely assign this energy to 

 such attractions instead of to the strains and 

 stresses in the ether." 



Among the important papers presented before 

 this section were : " The Period of Vibration of 

 Disturbances of Electrification of the Earth," by 

 J. F. Fitzgerald ; " The Moon's Atmosphere and 

 the Kinetic Theory of Gases." by G. H. Bryan : 

 " Reflection from Corrugated Surfaces " and 

 " Grinding and Polishing of Glass Surfaces," by 

 Lord Rayleigh ; " On the Piezo-Electric Prop- 

 erty of Quartz " and " On a Piezo-Electric Pile," 

 by Lord Kelvin ; " Caustic Curves," by J. Lar- 

 mor ; " Sun Spots and the Solar Envelope," by 

 Rev. F. Hewlett ; " On Electric Interference 

 Phenomena," by E. H. Barton ; " On the Passage 

 of Electric Waves through Layers of Electro- 

 lyte," by G. H. Yule : " On the Magnetic Shield- 

 ing of Two Concentric Spherical Shells," by 

 Arthur W. Rttcker; "The Construction of 

 Specula for Reflecting Telescopes," by A. Scha- 

 farik ; " Physics Teaching in Schools, by W. I'.. 

 Croft ; and " On Standards of Low Electrical Re- 

 sistance," by J. Viriamu Jones. Besides the fore- 

 going, reports of committees on special topics or 

 of individuals were received and discussed as fol- 

 low : Report of the Committee on Solar Radi- 

 ation ; report on our Present Knowledge of 

 Electrolysis and Electro-Chemistry ; report of 

 the Committee on Earth Tremors ; report of 

 the Committee appointed to investigate the 

 Earthquake and Volcanic Phenomena of Japan ; 

 and the report of the Electrical Standards 

 Committee. Also the question of " Physics 

 Teaching in Schools " formed the theme for dis- 

 cussion at one of the sessions of this section. 



B. Chemistry. This section was presided over 

 by Prof. James Emerson Reynolds, M. D., Sc. D., 

 F. R. S., of the University of Dublin. He called 

 attention to the fact that at the Nottingham 

 meeting of the association in 1866 the president 

 of the chemical section had spoken on the place 

 of " Chemical Science in Medical Education." 

 There was still a need for a fuller chemical edu- 

 cation in medicine along the line of principles 

 rather than knowledge of compounds. In the 



