Jan. 23, 1879] 



NATURE 



267 



This constant temperature of the .-urface having been once 

 established, the internal parts would be hotter than the crust, 

 and their heat must then necessarily, by the law of conduction, 

 pass from the hotter to the cooler region, and so into and through 

 the crust, and be radiated away from the surface into space, 

 the kind of action which I illustrated in my former letter by the 

 disper-ion of a crowd. Thus the interior woidd tend to fall to the 

 already established temperatvure of the surface, and thenceforth 

 tend to cool more rapidly than the " crust." For the nearer a 

 stratum lies to the siu-face, the less cooling will be requisite to 

 bring it down to the temperature of the surface. To take the 

 extreme case ; after the lapse of an infinite time the whole globe 

 would eventually become of the temperature which the surface 

 assumed at that already far-dLstant epoch, and has maintained 

 ever since. 



When the superficial strata had early assumed their nearly 

 permanent temperature, they will concomitantly have attained a 

 corresponding permanent volume, which will afterwards have 

 1 roved too large for the cooling interior, so that they must, in 

 subsiding, have become wrinkled. To this extent, then, I think 

 Mr. Wallace's objections are untenable. Here, however, enters 

 the question, so difficult to answer in nearly all geological prob- 

 lem=, of " How much ? " For my part, I think I have proved 

 that the mere cooling, though a vera causa, would not be of 

 itself a sufficient cause to account for the inequalities existing 

 now, at what must be, judging by the enormous store of heat 

 still within the earth, a comparatively early stage of the 

 cooling.i O. Fisher 



Harlton, Cambridge, January 18 



Leibnitz's Mathematics 



Ix Nature, vol. xix. p. 196, I see there is a letter respecting 

 the claims of Newton and Leibnitz to the discovery of the dif- 

 ferential calculus. In \iew of any future discussion of this 

 matter it seems to me that the following extract from a letter of 

 Leibnitz to James Bernoulli is worth the consideration of the 

 advocates of both claimants : — 



"Ego qui semper hoc habui eximium, ut essem mortalium 

 docillimus, sxpeque luce ex unius magni viri verbis pauculis 

 hausta innumera mea meditata nondnm matura delevi ; statim 

 arripere monita summi mathematici." — Ex epistola Leibnitii ad 

 Jac. Bernoullium, April, 1703, data. 



The sense of this passage may, I think, be fairly rendered into 

 English as follows : — 



" I [am one] who ever regarded this as most important, that I 

 should be most apt of mortals to receive instruction, and fre- 

 quently light having been drawn from a very few words of a 

 great man, my countless meditations not yet ripened I have 

 blotted out forthwith to seize upon the hints of the most eminent 

 mathematician."' James Bottomley 



Lower Broughton, near Manchester, January 13 



I HOLD myself prepared to make good my own assertions, and 

 to respond to Mr. A. B. Nelson's call as soon as I know whether 

 Prof. Tait has abandoned his position, or, if not, what he has to 

 .say in justification of his proceeding in denying Leibnitz to be a 

 mathematician and affirming him to be a thief. 



I am sure the editor will allow me to reply to his postscript. 

 It is certainly not to be presumed, as a matter of course, that 

 when Prof. Tait "lets pass such a challenge he has given up 

 his point." But I do insist upon it that this "hard-worked 

 scientist " had no right to pass it by after having provoked it. 

 He put himself in the wrong, and I left him there. 



But as to this being a question of merely "antiquarian 

 interest," I take leave to deny it. I revere the name and intellect 

 of Leibnitz, and I, for one, have a human interest in clearing 

 that name from a foul slander. Nor should we pass by the 

 main issue to discuss the collateral question which the editor 

 raises in respect of Gregory's series. C. M. Ingleby 



Valentines, Ilford 



Gensan Degrees 



It having come to the certain knowledge of the Faculty of 



Philosophy in the University of Erlangen that a fraudulent trade 



is earned on in England under a pretence of procuring doctor 



diplomas of the said Faculty, I consider it in the interest of the 



public hereby to make it known that promotions in absentia are 

 not conferred in that faculty, and that no one in England, or 

 elsewhere, is, or has ever been, authorised to confer or n^otiate 

 for the conferring of such diplomas. 



E. LOMMEL, 

 Dean of the Faculty of Philosophy, 

 Erlangen, January 14 University of Erlangen, Bavaria 



' C.-.mb.i.'ge /v. .7. T 



iius., V I. x-i. ;ar 2. 



Feeding a Python 



The following details of a recent attempt to feed a python 

 now at the Raffles Mxiseum, Singapore, may be of interest as 

 upsetting previous ideas as to the certainty of that reptile's 

 attack : — 



The python in question is a fine specimen caught on the 

 island, for the sake of the reward given by the police in such 

 cases, and measures about 22 feet in length. It has been in my 

 charge for about two and a half months, during which time it 

 has not been fed. About ten dajrs since it commenced casting 

 its skin, and, as is usual after that proceeding, was unusually 

 lively, snapping at a stick put into the cage, and in one or two 

 instances narrowly missing the attendant's hand. The reptile, I 

 should mention, escaped from its cage just before casting, but 

 having taken refuge beneath some odds and ends of timber near 

 the museum, was recaptured without difficulty, and was then 

 placed in a cage about 5 feet square every way. 



A pariah dog having been obtained, it was introduced, 

 muzzled, into the cage, lie muzzle being then slipped. While 

 entering, the snake struck twice at the dog's hind-quarters, but 

 without seizing it. The dog crept into a comer and sat down. 

 Two or three more blows were then made by the snake, but, as 

 before, without gripping, and the dog was then seen to have been 

 struck by the teeth on the fore-quarters, the punctmres sHghtly 

 bleeding. For nine successive times the snake struck at the dog with 

 the same ill-success, and as it was then growing dark, the shutter 

 of the cage was closed. Early next morning the snake was 

 found coiled round the dog, which it had killed and commenced 

 to swallow ; but a Malay attendant having touched the python 

 with a rod, it untwined itself and retreated to a comer of the 

 cage, refusing to again touch its prey. 



I may be misinformed, but have always understood that snakes 

 of the python or boa tribe seldom renew their attacks if the first 

 fails ; and I shall be glad if you can direct me to any published 

 experience on the subject. The python in question is a male. 



Singapore, November 25, 1878 N. B. D. 



Shakespeare's Colour Names 



I FEAR it would be somewhat rash to convict Shakespeare of 

 colour-blindness, or even vagueness in the use of colour-names, 

 solely on the evidence of the Nurse in "Romeo and Juliet" — a lady 

 who is the Mrs. Malaprop of the "play, and whose extraordinary 

 faculty for the confusion of terms may perhaps have contributed 

 somewhat to the "merriness" with which she credited her 

 husband. It is possible that the Nurse — in the passage quoted 

 by Mr. J. J. Murphy (Nature, vol. xix. p. 197) — meant to 

 convey the idea of a hazel eye, which would not be far removed 

 in colour from that of an eagle, but also often has a slight 

 tendency to a greenish hue. The nurse, not being particular as 

 to the precision of her descriptions in general, refers to it as 

 green. 



It is likely besides that Shakespeare deliberately intended the 

 incongruity, just as in the "Midsummer Night's Dream" he 

 makes the bumpkin who acts Thisbe in that piece of "very 

 tragical mirth," Pyramus and Thisbe, lament 



' ' Those lily brows. 

 This cherry nose. 

 These yellow cowslip cheeks, 



His eyes zvere green as leeks." 



This passage indeed shows that Shakespeare knew perfectly 

 well the chromatic meaning of green. 



A very cursory glance through Shakespeare will show innu- 

 merable lines where colours are referred to in their trae and 

 exact sense. 



Here are a few passages selected with special reference to the 

 colours green and blue. 



Prospero's description of the witch Sycorax : — 

 " This blue-eyed hag." — Tempest, i. sc. a; 



(The ider.l Scandinavian witch.) 



