3^4 



NATURE 



[Feb, 20, 1879 



America is represented by a dozen or more species. Now, 

 though an Erebia (E, Tyndarus, var.) occurs as far south in 

 Europe as the Sierra Nevada, not a single species of any ©f these 

 three genera occurs in North Africa, although the Atlas Moun- 

 tains would seem eminently well suited for such Alpine insects. 

 In this case, then, it seems clear that the same cause — the barrier 

 of the Mediterranean — which in the case of the miocene flora 

 of Europe prevented any further retreat south, has operated to 

 prevent any similar southerly spread amongst the victorious 

 invaders from the north which pressed on the retiring host. 



With regard to the general similarity in facies and richness 

 between the East American and East Asiatic tree-flora, certain 

 facts pointing in the same direction will at once occur to the 

 zoologist. Thus the Menopomas of the Ohio and Alleghany have 

 their only near relations in the gigantic Sieboldias of north-east 

 Asia, one species of these occurring in Japan, the other being one 

 of Pere David's discoveries in Moupin, Similarly with the 

 genus Polyodon amongst ganoids. Only two species of this genus 

 are at present , known, P. folium, inhabiting the Mississippi, 

 P. gladius the Yang-tse-kiang. The recent discovery of at 

 least two species of Scaphi rhynchus in Turkestan makes it 

 pirobable that ere long species of that Americo -Asian genus will 

 be found in the Chinese rivers as well. The parallelism in the 

 case of the salamanders is particularly interesting, when one 

 remembers the celebrated Andrias Scheuchzeri of the Qiningen 

 beds, and it tends to favour the view that at that time practical 

 identity in the forms of animals and plants reigned throughout 

 the northern temperate zone. W. A. Forbes 



Cambridge, February 14 



P.S. — The reported discovery (Nature, vol. xix. p. 351) of 

 a true alligator in the Yang-tse-kiang, will, if confirmed, add a 

 sdU more r^navkai>le case tO' those mentioned above. 



Leibnitz and the Royal Society 



Prof. Tait and myself ought not to be at issue on this ques- 

 tion. I suppose we "both want to get at the facts ; and, for my 

 part, I have no more desire to whitewash a foul reputation than 

 he can have to blacken a fair one. Where. we differ appears to 

 be, as to how far . Leibnitz's reputation can stand the test of 

 facts. The question, however, is not whether Leibnitz acted 

 disingenuously in respect to Gregory's series, or any other sub- 

 -crdlhate matter, but whether he was indebted to something of 

 Newton's, suiTeptiti'ously imparted to him, for his differential 

 calculus. If the grounds upon which that charge was made are 

 swept away, there is an end of it. But if, on the other hand, 

 that is not found feasible, and evidence to cliaracter becomes a 

 factor in the final decision, then it is right to examine into those 

 subordinate matters. Till then, I,^ for one, decline to touch 

 them. At the same time let me say that I never undertook to 

 be bail for Leibnitz's impeccability. All I said or say is, that 

 on the published .facts I believe that Leibnitz was led to the 

 calculus by his own honest speculations, and had not the means 

 of stealing from Newton, had he been that way disposed. But 

 there are so many relative papers still unpublished, but publish- 

 able, that it is impossible to arrive at a true decision till at least 

 some of them have Been submitted to an authorised tribunal. 



Prof. Tait recommends me to repeat the fruitless attempt of 

 Dr. Slowmah. 'I' decline to follow the example of that 

 ominously surnamed savant] for it is contrary to precedent that 

 the pursuer should ask the defender to show his hand ; and I 

 am quite sure that " the proper authorities " abroad have too 

 much sense to take the initiative. So I appeal to the Coimcil 

 of the Royal Society of 1879 (not that of 17 12, as Prof. Tait 

 ■gives it), and I do so for these two reasons : — 



1. The so-called Commercium of 1712, which was merely a 

 ■staternent, arriving at no decision on the principal, question, 

 cbntained several allegations (apparently inconsistent with 

 known facts) which give colour to the charge against Leibnitz ; 

 it is then an obvious duty on the part of the Royal Society, who 

 were on the occasion represented by the Committee, to give 

 the proof, or make the reparation. 



2. The first-published charge against Leibnitz, which was 

 made by Wallis in 1695, was based on allegations said to have 

 been derived from papers and letters in the possession of the 

 Royal Society ; it is. but fair, then, that those papers and letters 

 should be published. 



I therefore once more respectfully urge upon the Royal Society 

 to reopen the main question, and publish such of the relative 



papers, &c., in their possession as directly bear upon the original 

 charge. C. M. Ingleby 



Athenaeum Club, February 8 



Ear Affection 



The experience of " P." as given in Nature, vol. xix. p. 315, 

 is physiologically interesting, and by no means usual. Before 

 attempting an explanation it may be as well to assume that only 

 one of '|P.'s" ears was affected by the disorder, as by this 

 hypothesis we get the greatest possible divergence from the 

 healthy state. It would have been easy to ascertain which was 

 the faulty organ at the time by requesting a musical friend to 

 listen while "P." vocalised the note of the tuning-fork as con- 

 veyed to him by each ear separately. The discordant ear would 

 then have been revealed. 



The fault of hearing must have been due either to some 

 mechanical misadjustment of the auditory apparatus, by which a 

 wrong sensation was conveyed to the brain, or else to some 

 deep-seated brain or nerve lesion, which led to a faulty concep- 

 tion of the original sound. Let us consider briefly the first of 

 these cases. 



From the exceedingly scanty description of his disorder given 

 by "P." I gather that the discord was mostly conspicuous when 

 the note was high pitched (such as when whistled). Now it 

 sometimes happens from paralysis of the chorda tympani nerve, 

 or even from occlusion of the Eustachian tube, that the tension 

 of the ear-drum is pretematurally increased. Such affections, 

 as aurists well know, frequently intensify to a distressing degree 

 the hearing of high pitched notes, whilst they correspondingly 

 diminish the sound of the lower tones of the chromatic scale. 

 This result is probably obtained by the fact that the tense mem- 

 brane responds more readily to the rapid vibrations of the higher 

 tones than it does to those of a slower rate. We must also 

 remember that the power of lessening the tension of the mem- 

 iH-ane is in such cases very seriously impaired, and, as a conse- 

 quence, the power of adjustment also. I do not suppose that in 

 "P.'s" case there was any actual paralysis of the tympanic 

 muscles, but it is just possible that there may have been a 

 certain degree of misadjustment of the drum of the affected ear 

 due to a feeble and imperfect contraction of one or the other of 

 the muscles referred to. If the disorder was, as I surmised, ac- 

 companied with great tenseness of the membrane, the laxator 

 tympani would be the faulty muscle. We might, I believe, 

 under such circumstances, expect the ear-drum to vibrate dis- 

 cordantly in response to a note, for Helmholtz's experiments 

 with stretched strings would suggest that this is feasible withui 

 certain limits. As a matter of fact this discordance is rare, and 

 therein rests the interest of " P.'s " case. 



I can scarcely believe that in his case any of the deeper struc- 

 tures of the ear were seriously implicated, otherwise he would 

 hardly have made such a rapid and complete recovery as he did. 



Brighton, February 10 W. AiNSLiE HoLLis 



Your correspondent "P." (Nature, vol. xix. p. 3^15) desires 

 an explanation of the phenomenon of alteration in the pitch of 

 sounds, which he has experienced in his own person whilst 

 suffering from temporary deafness. Yoiu: second correspondent 

 on this subject, Dr, Wallich (p. 340), was under my observation 

 at the time of his experiencing the same peculiar and comparatively - 

 rare aberration, and I was able myself to verify his statements. 



I propose with your permission to give an explanation which 

 appears satisfactory to myself, and hope it may be so to your 

 correspondent "P." 



Persons suffering in this way find that sounds heard by the 

 affected ear appear to be sharper or flatter than their true pitch 

 as heard by the other ear, and hence a sound may even appear 

 double. " ■ ' ! 



The internal ear, or labyrinth, must be the part affected, and " 

 in all probability it is the cochlea which is at fault. Now most ■ 

 authoi-ities are agreed that the pitch of a sound is appreciated by 

 the cochlea in the following manner. Each tone, or division of 

 a tone, has its corresponding portion on the spiral lamina of the 

 cochlea, which under ordinary circumstances can only be aflected 

 by that tone. So that the sound-wave produced by a certain 

 tone passes along the keyboard (as it were) of the spiral lamina 

 until it reaches its own key, which it strikes or so affects as^ to 

 cause an impression to be sent from that portion of the lanaina 

 to the brain. Hence the appreciation of variation in the pitch 

 of sounds. fc ■ 



