March 28, 1878] 



NA TURE 



421 



wildly attacked by Prof. ZoUner in the Pre/ace to his book 

 on Comets. To that attack Prof. Helmholtz replied in a 

 very admirable article, of which a translation has already 

 appeared in Nature (vol. xi. pp. 149, 211). 



The great crime which according to Prof. ZoUner was 

 committed, was a double one. Sir W. Thomson and I 

 ventured to express an opinion (to which we still adhere) 

 unfavourable to theories such as that of Weber : — and 

 Prof. Helmholtz so far forgot his duty as a German as to 

 be responsible for the reproduction of our work in his 

 native tongue ! As we now know that the promulgation 

 and extension of Weber's Theory has been the object of 

 Prof. Zollner's life-work, perhaps it was not unnatural 

 that he should complain of such conduct. But it is quite 

 another thing when, after being completely demolished 

 from the scientific point of view, he returns to the attack 

 in another style —bringing against the various persons 

 named charges of a totally different character — though 

 all equally groundless. 



A great many of these arise undoubtedly from imper- 

 fect acquaintance with the English language. Thus, to 

 take a ludicrous one. Prof. Zollner evidently imagines that 

 " smoke-rings " must be formed with tobacco-smoke ? 

 And he fancies that it was in a smoking party that Sir 

 W. Thomson hit upon his hypothesis of vortex atoms. 

 For, after translating part of Thomson's own account of 

 his theory, he says that a " skilled and powerful tobacco- 

 smoker was necessary to the experimental verification 

 of it." 



Smokers, to whose charmed circle Prof. Zollner evi- 

 dently does not belong, can alone judge how skilled and 

 powerful they would have to become before they could 

 produce from their own lips the vortex rings, full of sal- 

 atntnoftiac crystals and somewhere about six or eight 

 inches in diameter, which Sir W. Thomson describes in 

 the paper referred to. But Prof. Zoilner comes back to 

 this notion, as he docs to others, with absolutely " damn- 

 able iteration." Here is an instance (p. 103) which we 

 paraphrase as follows : — 



" The reader will note that * Tobacco-smoke ' and a 

 * creative act ' are the inseparable companions of Thom- 

 son's Vortex-atoms : — although in the whole of Helm- 

 holtz's paper, on which Sir W. Thomson has erected the 

 airy structure of his hypotheses, there is not a single 

 passage in which such things are alluded to. 



" Since Sir W. Thomson and the mathematical sup- 

 porters of his hypotheses continually employ tobacco- 

 smoke for the explanation of their views, 1 also may be 

 permitted to employ the same medium to make clear my 

 notions. Were I to describe the feelings with which i 

 crossed the threshhold of the Vortex-world of Thomson 

 after leaving the clear and bright Thought-world of 

 Newton, Kant, and Faraday, I could not succeed better 

 than by comparing them to those of the Alpine traveller 

 who leaves the enlivening freshness of the clear mountain 

 air to enter the tobacco-laden atmosphere of a muggy 

 beerhouse ! " 



We next have Thomson's (and.Helmholtz's) speculations 

 as to the origin of life on the earth :— once more over- 

 hauled and torn to shreds. Then the unfortunate "lumi- 

 nous corpuscle " of Thomson and Tait has again to 

 perform its antics — but in a somewhat new phase. For it 

 is now shown to be due to the same inaccuracy of thought 

 (Denkfehler) as the " moss-grown fragments." 



" Only the yet undeveloped understanding of a child 



can content itself with such hypotheses, as it does with 

 the answer to the child's question, ' Where did the new- 

 born little brother or sister come from .^ ' The mother 

 soothes the childish causation-excitement with the answer, 

 ' The Stork brought it ' : — on the correct presumption that 

 the child will not farther inquire whence or from whom 

 the Stork received the infant." 



So far as I can judge without an attentive perusal of 

 the whole 732 pages of the work {Erster Band), such as, 

 amusing though it is throughout, I cannot spare time to 

 bestow, Prof. Zollner seems to think that Clerk-Maxwell, 

 Thomson, and myself believe in the existence of those 

 imaginary beings (invented by Maxwell, and called 

 Demons by Thomson) who were introduced for the 

 purpose solely of showing the true basis on which the 

 Second Law of Thermodynamics has to be received as 

 a fact in physical science ! Hence we are treated to a 

 whole Chapter called " Thomson^s Ddmoncn und die 

 Schatten Plato's." ^ 



But it was well that this Chapter should be written. 

 For Prof. Zollner has recorded in it a discov^ery of the very 

 first order : — if it be correct. He has held the two ends 

 of a cord (sealed together) in his hand, while trefoil knots, 

 S^enuine IRREDUCIBLE TREFOIL KNOTS, of which he 

 gives us a picture, were developed upon it ! He shows 

 us the reasoning by which he was led to predict the 

 possibility of this very wonderful achievement— absolutely 

 unique in character, so far as I know, throughout the 

 whole range of science. Prof. Klein, of Munich, some 

 time ago showed, as is well known, that knots cannot 

 exist in space of four dimensions. Hence Pro''. Zollner 

 was led to conclude that beings (not, of course, ThonisoiCs 

 Ddmoncn nor die Schatten Plato's, for these are unscien- 

 tific, and therefore impossible) in space of four dimensions 

 could put an irreducible knot on an earthly string of which 

 the ends were fastened together ! It is some time since 

 the Astronomer-Royal for Ireland told me his jocular 

 mode of arguing from Klein's discovery : — viz., that all the 

 secrets of the spiritualistic "rope-trick" could be at once 

 explained by supposing that z//j-/(/<? the mysterious cabinet 

 (in which the tambourines and the musical boxes fly 

 about) space was of four dimensions — so that the well- 

 corded performers were at once loosed from their bonds 

 on entering it ! But Prof. Zollner (with the assistance of 

 the spiritualists) has tied knots by means of beings who 

 exist in four dimensional space ! ! ! Those who tied can 

 of course loose, so that there is now (thanks to Prof. 

 Zollner and the spirits) no such thing as an irreducible 

 knot ! 



I need say nothing of the treatment which Prof. Zollner 

 bestows on other scientific men with whom he has the 

 misfortune to disagree : such as the imaginary execution- 

 scene (pp. 377-416) of a distinguished Physiologist I 

 Plain men in this country, and in Germany also I doubt 

 not, have uncomfortably plain terms for such outburst-. 

 But such things are not for a scientific journal. I can 

 hardly divest myself of the impression that Prof. Zollner, 

 in spite of his oft-expressed utter detestation of " Jokelets" 

 of all kinds (Witze, Scherze, &c.) has been led by his 

 feelings of " sittlicher Entriistung" to attempt the perpe- 



■ This is not ihe place to continue discusbions with Pro''. CIau>iuk, but 

 the reader of Prof. Zollner's book stiould bt; warned that, extensive as 'S his 

 reading, it does not always seem to include the most cogent argumenc: 

 which tiave been presented on one or other side in several controversies of 

 which he undertakes to give an account. 



