198 



NATURE 



[December 28, 1893 



deduction and Hamilton's Principle of Least Action. But the 

 limitation is required by the postulate, viz. the Principle of 

 Least Action, not by the deduction. Clausius expressly state? 

 {Phil. Mag. vol. xliv. (1872) p. 365) that his deduction hDJd; 

 good for systems to which the Principle of Least Action is not 

 directly applicable, and in consequence he claims that his 

 equations involve a new principle which is of more general ap- 

 plication than Hamilton's Principle {vide Report, § 16). I think 

 there can be little doubt that Clausius had in his mind the very 

 biection which Mr. Burbury now raises, and that it was in order 

 to mfet it that he claimed this generalisation. 



The assumption as ^o the conservative nature of the forces is 

 not required except in § 17 of the Report, and at the end of 

 that paragraph two methods of avoiding it are suggested. One 

 is to assume that the force-function can be varied with the time, 

 the othei; is a method adopted by Von Helmholtz. 



If we allow the force-function to be varied with the time, 

 then in Mr. Burbury's case (of a column of gas held down by a 

 piston of constant mass) the potential of gravity can be altered 

 and therefore the weight of the piston is disposable. This dis- 

 poses of Mr. Burbury's objection, and it only remains to consider 

 the investigations given at the beginning of § 17 of the Report. 



Clearly the Second Law of Thermodynamics cannot be de- 

 duced from studying the behaviour of gas under constant pres- 

 sure. To establish it we must make the working substance 

 undergo a reversible cycle in which heat is absorbed and ex- 

 ternal work performed. To do this we attach the piston to a 

 crank as in an ordinary steam engine, and make it turn a wheel 

 which raises a weight by means of a windlass. Here we have 

 a strictly conservative system, and one to which the arguments 

 of § 17 are therefore strictly applicable. And for every single 

 turn of the wheel we have 



/" 



(I) 



rS = o 



T 



a relation identical in form with that which expresses the 

 Second Law. 



It seems to me that the real objections to Clausius' deduc- 

 tions are far more intricate and far less easily disposed of. The 

 difficulty of assigning a physical meaning to the quisi-period i 

 is one of them, and there are other difficulties connected with 

 the interpretation of T as absolute temperature when intermole- 

 cular forces are taken into account. All these difficulties are 

 alluded to in my Report, and they are not peculiar to the hypo- 

 thesis of " quasi-periodic" motions ; similar difficulties exist in 

 some form or other in most so-called "proofs of the Second Law." 



It may be interesting to mention that a proof of the Second 

 Law based on the virial equation 



/z/ = 1 (T -f 22 (JRr)) 

 was given by R. C. Nichols in the Philosophical Magazine for 

 1876 (v. Series I. p. 369). I hope later on to deal more fully 

 with that portion of Mr. Burbury's letter which relates to the 

 " virial proof. " G. H. Bryan. 



December 21. 



Flame. 



I HAD hoped that after disavowing the unpleasant interpreta- 

 tion which had been put upon his first letter. Dr. Armstrong 

 would have done me the honour, and himself the justice, of 

 indicating precisely where he disagreed with my scientific 

 arguments. Instead of doing so, he has imputed to me a sensi- 

 tiveness to criticism so excessive that he feels it best to retire 

 from the controversy with a mere statement that our standpoints 

 are different. I must leave it to the readers of Nature to judge 

 whether Dr. Armstrong has any longer the right to claim a 

 standpoint. 



Mr. Newth willfindafullerdiscussionof my views about flame 

 in the Journal of the Chemical Society for 1892, pp. 204-226. 

 If after reading that he still has difficulty in understanding the 

 fundamental points of my work, I shall be glad to help him if 

 he will communicate with me privately. With a little care, 

 Mr. Newth will find it quite easy to separate the two cones of 

 a carbon monoxide-air flame in the ordinary apparatus without 

 the use of a gauze cap. The air must be turned on very gradu- 

 ally. In the case of the hydrogen-air flame it is best to dilute 

 the gases with nitrogen, as recommended in my first paper. 



I am sorry that anyone should think I have slighted Dr. 

 Frankland's work. I can, however, understand, and even 

 admire, Mr. Newth's excessive zeal in the matter. 



Arthur Smithells. 



NO. I 26 I, VOL. 49] 



"The Zoological Record." 



We are delighted to find such a consensus of opinion as to 

 the desirability of retaining pal^Dzoology in the Zoological 

 Record. The recorders whom we have consulted, the editor, 

 and now the secretary of the Zoological Society, all have 

 expressed themselves in its favour. The question therefore is 

 purely one of finance. Under these circumstances the publica- 

 tion of the correspondence with the Geological Society is of 

 great interest, and the only addition that we could suggest would 

 be the publication in your columns of that poverty-stricken 

 society's balance-sheet. 



We should like, however, to point out that the Zoological 

 Record appeals to the Geological Society, not merely on the 

 ground of its palceDntological contents. Palaeontologists go to 

 the Record to learn what the neontologists are doing, quite as 

 much as to read the titles of their own papers. Under any 

 circumstances, then, the 'Zoological Record has some claim on 

 the Geological Society, and we must all regret that financial 

 distress prevents the Society from acknowledging that claim. 



But the Record Committee of the Zoological Society need 

 not despair; for the Record has no less claims on many other of 

 our learned societies, and, by the converse argument, the 

 inclusion of palseozoology merely strengthens those claims. 

 Every biologist should be grateful to those who bring to his 

 notice literature that he would otherwise never hear of. Apart 

 from this, one-third of the volume is devoted to entomology. 

 Why should the Entomological Society not be invited to contri- 

 bute? Then there are the Royal and the Linnean Societies, and 

 the British Association ; the Microscopical, we would mention, 

 did it not already do excellent work of a similar kind. At any 

 rate, surely five of these bodies could be prevailed on to sub- 

 scribe ^20, or even £6,0 a-piece. The Zoological Society 

 appeals through its Record to hundreds of workers who do not 

 belong to it. It has long done an admirable work, of which 

 it will never lose the credit. Everyone should sympathise with 

 it in its present attempt to perfect this work, and should not 

 permit it to suffer so large a pecuniary loss in that attempt, 



December 17. R. I. Pocock;. 



F. A. Bather. 



On the Bugonia-Superstition of the Ancients. 



Last August, I published in the Bulletin Soc. Entomol. 

 Italiana, 1893, p. 186-217, an article entitled " On the Bugonia 

 of the Ancients, and its relation to Eristalis tenax, a two- 

 winged insect." I desire to collect some more materials on that 

 subject, in view of a second edition, and I would be very grate- 

 ful to readers of Nature who may be able to give me assistance 

 in that matter. 



The information I require maybe expressed in two questions : 



(i) Whether travellers in out-of-the-way places in Europe or 

 Asia have not come across vestiges of the superstition about 

 oxen-born bees, still lingering among primitive people? 



(2) Whether readers of Oriental literature have not come 

 across passages evidently referring to this superstition, like the 

 passage I reproduce here as an example. I found it in the 

 "Golden Meadows" of the Arab traveller Massoudi (died in 

 Cairo, 955), translated by Barbier de Meynard and Pavet de 

 Courteille, Paris, 1861, vol. iii. p. 233. It relates a conversa- 

 tion which took place in Arabia, and of which this is a fragment. 

 " ' Had the bees, which produced this honey, deposited it in the 

 body of a large animal,' asked Yiad? The surveyor answered : 

 ' Hearing that there was a hive near the sea-coast, I sent people 

 to gather the honey. They told me that they found at that 

 place a heap of bones, more or less rotten, in the cavity of 

 which bees had deposited the honey that they brought with 

 them.'" 



I have sent separate copies of my paper to the Geographical, 

 Linnean, and Entomological Societies in London, to the 

 Natural History Museum, South Kensington, to the Athenaeum 

 Club, and to many friends in England. I should be happy to 

 send a copy to anybody interested in the subject. 



C. R. Osten Sacken. 



The Earliest Mention of the Kangaroo in Literature. 



I take advantage of the present opportunity to put another 

 question to zoologists. In the same book of Massoudi, whom I 

 quoted in the previous notice, I found the following passage 

 (vol. i. p. 387): — "El Djahiz, in his 'Book on Animals,' 

 relates that the female rhinoceros is pregnant for seven years. 



