December 8, 1898] 



NATURE 



139 



iiagnetic state of the surface This result was of the highest 

 iheoretical interest, and it has been a matter of admiration and 

 wonder to subsequent investifjators that Dr. Kerr should have 

 l>cen able to learn so much with the comparatively simple and 

 ineffective apparatus at his disposal. 



' Both of Dr. Kerr's great researches have been the starting 

 points of numerous inquiries. His experiments on electrical 

 stress have been repeated and extended by (Gordon, (^)uincke, 

 Kontgen, and others, while Kitzgerald, Kighi, Kundt, I.orentz, 

 Sissingh, Zeeman, J. J. Thomson, Du Hois, Goldhammer, 

 Drude and Leathern, are among those who have been occupied 

 with the extension or theoretical meaning of his work. 



Dr. Kerr's researches rank among the most important of 

 those which have been made since the lime of I'araday. 



The other Koyal Medal is conferred on Mr. Walter (lardincr, 

 who has taken a leading part in what is perhaps the most im- 

 portant recent advance in Vegetable Histology, namely, the 

 discovery that the protoplasm in the tissues of plants is con- 

 tinuous from cell to cell, and not broken up into isolated portions 

 ,hy the cell-walls. Ilis first work on the subject dates from 1882, 

 when he published in the Quarterly /oiinial of Microscopical 

 Science a short paper on " Open Communication between the 

 Cells in the Pulvmus of Mimosa pmiica." Up to that time 

 ])rotoplasmic continuity in plants had only been recognised in 

 the special case of the sieve-tubes and in the endosperms of 

 three species ; and even in these instances the evidence that the 

 > connecting threads were really of protoplasmic nature was not, 

 in Mr. (Jardiner's opinion, conclusive. 



In 1883 he presented to the Royal Society an extensive 

 memoir "On the Continuity of the Protoplasm through the 

 Walls of Vegetable Cells " [Phi/. Trans., pt. 3, 1883), in which 

 he demonstrated that this structure is constant in the endosperm, 

 and that it also occurs in various tissues of the plant. Mr. 

 Gardiner at that time thought it probable that the phenomenon 

 might be of universal occurrence, and dwelt on its great 

 physiological significance. 



In the nuantinu- other observers took up the subject, and the 

 generality of protciplasmic continuity in plants came to be widely 

 recognised by botanists. Mr. Gardiner, however, was severely 

 critical of his own methods and results, and was not satisfied 

 that the evidence, though conclusive in so many cases, was 

 strong enough to bear the weight of so wide a generalisation. 

 He therefore set himself, within the last few years, to re-in- 

 vestigate the subject, with the aid of more refined processes 

 which he hail adapted and elaborated. 



The results of his renewed work were communicated to the 

 Royal Society last year, in a paper on "The Hi.stology of the 

 Cell-wall, with special reference to Ihe Mode of Connection of 

 Cells" [Roy. Soc. Proc, vol. 62, p. 100). In this work he 

 shows for the first time, that the connecting fibrils of protoplasm 

 can be demonstrated with certainty in all kinds of vegetable 

 tissues, and he is also enabled to make the imporlant statement 

 that " the threads appear to be present ah initio." 



Mr. O.-irdiner has done much good work in other departments 

 of the Histology and Physiology of Plants, notably on glandular 

 structures; on the functi in of tannin ; on protoplasmic con- 

 tractility ; and on the phenomena accompanying stimulation 

 in insectivorous plants. His scientific reputation, however, 

 rests chiefiy on the fact that to him, more than to any other in- 

 vestigator, is due the discovery of the continuity of protoplasm in 

 plants — a discovery which essentially modifies our whole con- 

 ception of vegetable organisation. 



The Davy Medal is awarded to Prof. Johannes Wislicenus for 

 his numerous and important contributions to Organic Chemistry, 

 embodied in a series of papers extending over the last thirty- 

 five years, and published in the Hericlile of Ihe German Chemical 

 Society, I.iebig's Anna/en, and elsewhere. The researches 

 undertaken by Prof. Wislicenus and his pupils, in.spired by the 

 zeal of their master, have flowed, almost without intermission 

 during the period mentioned, from the laboratories of Ziirich, 

 Wiirzburg and Leipzig. Among his earlier work may be men- 

 tioned his classical researches on the lactic acids, which finally 

 settled the much-debated questions concerning the combination 

 of acid and alcoholic properties in oxy-acids in general. These 

 re.searches threw much light on the subject of the isomerism of 

 theoxy|>ro|iionicaciils. He ascertained the nature of the action 

 of silver oxide on j8-iodopropionic acid, while his improved .syn- 

 thesis of ordinary lactic acid from aldehyde, and of fl-oxy- 

 propionic acid from glycollic chlorhydrin, established the 



NO. I 5 19, VOL. 59] 



relations of these acids to their respective radicles, ethylidene 

 and ethylene. His study of sarcolactic acid was a notable 

 contribution to the subject of the optical activity of organic 

 compounds, and resulted in the important di.scovery for the 

 first time of two substances having a structure of proved chemical 

 identity, and yet possessing different physical properties. 



The prominent part taken by Wislicenus in unravelling the 

 reactions concerned in Ihe formation of aceto-acetic ester, and 

 in the application of this compound as a synthetical agent, is 

 well known to all chemists. He devised a practical method 

 for its preparation, and was the first to use the isolated sub- 

 stance as the starting point of synthetical operations. He 

 defined the acid property of the replaceable hydrogen atom in 

 this ester, and its homologues, and devised the now familiar 

 methods for the use of the sodium derivatives in organic syn- 

 theses. He discovered the "acid " decomposition of the ester 

 and its derivatives, and established the conditions under 

 which the "ketonic" decomposition could be eflfectcd. He 

 utilised his methods for the synthesis of compounds of the 

 most varied types, such as mono- and polybasic acids, both, 

 saturated and unsaturated, oxy-acids and ketonic acids, ketones 

 and alcohols. 



More recently the name of Wislicenus has become closely 

 associated with discovery in the new field of stereo-chemistry. 

 As early as 1869 he pointed out the insufficiency of the ordinary 

 "constitutional" formulae to explain the isomerism of ordinary 

 and active lactic acid, and clearly stated that the explanation 

 was to be found in the tridimensional arrangement of the atoms 

 in space. Van 't Hoft' states that it was this statement by Wis- 

 licenus which suggested to him the ideas which culminated in 

 his well-known theory of the asymmetric carbon atom. Wis- 

 licenus boldly advocated the introduction of geometrical con- 

 ceptions into the doctrine of the constitution of chemical mole- 

 cules, and in his memoir " Ueber die laumliche Anordnung 

 der Atome in organischen Molekulen," published in 1887, he 

 extended the hypothesis of van 't Hoff, and showed bow the 

 spacial arrangements could be determined in special cases. The 

 new ideas contained in this memoir had a most stimulating effect 

 on Ihe study of stereo-chemical isomerism, Of his own and his 

 pupils' work in this field may be mentioned investigations of the 

 tolane dichlorides, acetylene-dicarboxylic acid, the butylenes 

 and derivatives of crotonic acid. 



The Darwin Medal is given to Prof. Karl Pearson in recog- 

 nition of the great biological importance of his work upon the 

 Theory of Probability, and its relation to vital statistics. The 

 inijiortance of the theory of probability in dealing with the 

 problems of organic evolution was first seen by Mr. Francis 

 (Jalton Prof. Pearson's merit lies in the fact that he has so far 

 extended the mathematical theory of chance as to make it pos- 

 sible lo treat generally problems which could previously be 

 dealt with only in a few special cases. Prof. Pearson has 

 shown, in various memoirs published in the Pliilosopliical 

 Transactions during the last five years, that the amount and 

 frequency of organic variation, the degree of interdependence 

 between one variable organ and others, the phenomena of 

 heredity, and the intensity of selective destruction can be treated 

 (luanlituively by means of his development of the calculus of 

 probability ; and he has given examples of the treatment of 

 variation and inheritance in man, and in a number of animals 

 and plants. 



A calculus by which the fundamental phenomena 01 organic 

 evolution can be treated quantitatively provides an engine of 

 biological research of a new and powerful kind, and, as a 

 stimulus to new and more accurate investigation of the phe- 

 nomena of organic evolution, it is of very great importance. 

 The hypothesis of natural selection has hardly been proved' 

 by Ihe direct demonstration of a selective death-rate, except in 

 few and simple cases. The demonstration of such selective 

 death-rate in more complex cases is rendered possible by Prof. 

 Pearson's work. Such demonstration is the natural and logical 

 seipiel to the work of Darwin himself, and there is a peculiar 

 fitness in awarding the Darwin Medal to the man who has made 

 it possible. 



The .Society next proceeded to elect the ofiicers and Council 

 fill the ensuing year. The list has already appeared in Naturk 

 (p. 39). 



In the evening the annual dinner took place at the Whitehall 

 Rooms. Among the guests of the Society who made speeches 

 were the Lord Chancellor, Lord Kitchener, and Lord Curzon. 



