212 



NATURE 



\7an. 14, 1875 



a process can be brought under ol-«ervation, and how this 

 is to be effected, are, of course, questions which, on the 

 argument of the EngHsh autho/s, fall to be answered by 

 those who undertake the direct proof of the existence of 

 the corpuscles. And whatever opinion one may form of 

 the stringency and fitness of this demand, it involves no 

 logical contradiction, which is the very point on which the 

 argument must turn if Mr. ZoUner is to make good his 

 case. 



I will mention one other objection of similar scientific 

 value, because it refers to Sir W. Thomson, though not to 

 a passage of this book. The point in question is whether 

 it is possible for organic germs to be present in meteoric 

 stones, and so to be conveyed to worlds which have 

 become cool. In his introductory address to the British 

 Association at Edinburgh, in the autumn of 1S71, Sir W. 

 Thomson characterised this view as "not unscientific." 

 Here, too, if an error has been committed, I must profess 

 myself a sharer in it. I had, in fact, indicated the same 

 view as a possible explanation of the transmission of 

 organisms through interstellar spaces at a somewhat 

 earlier date than Sir W. Thomson — in a lecture which was 

 delivered at Heidelberg and at Cologne in the spring of 

 the same year, but is still unpublished. If anyone chooses 

 to regard this hypothesis as highly or even as extremely 

 improbable, I have nothing to object. But if failure 

 attends all our efforts to obtain a generation of organisms 

 from lifeless matter, it seems to me a thoroughly correct 

 scientific procedure to inquire whether there has ever been 

 an origination of life, or whether it is not as old as matter, 

 and whether its germs, borne from one world to another, 

 have not been developed wherever they have found a 

 favourable soil. The physical reasons alleged by Mr. 

 ZoUner against the view in question are of very little 

 weight. He points to the heating of the meteoric stones, 

 and adds (p. 26) : " Thus, even if we suppose that when 

 the parent body was shattered, the meteoric stone covered 

 with organisms escaped with a whole skin, and did not 

 share the general rise of temperature, it was still necessary 

 for it to pass through the terrestrial atmosphere before it 

 could discharge its organisms to people the earth." 



Now, in the first place, we know from oft- repeated 

 observations that of the larger meteoric stones only the 

 very surface is heated in passing through the atmosphere, 

 the inner portions remaining cold, or even very cold. 

 All germs, therefore, that happened to be in cracks of the 

 stone would be protected from combustion in our atmo- 

 sphere. But even germs lying on the surface would 

 doubtless, when they entered the very highest and mcst 

 attenuated strata of the earth's atmosphere, be blown 

 away by the powerful current of the air long before the 

 stone reached the denser parts of the gaseous mass, 

 where the compression becomes great enough to generate 

 considerable warmth. And on the other hand, with 

 regard to the collision of two worlds as assumed by 

 Thomson, the first consequences of such an event would 

 be violent mechanical motions, while heat would be gene- 

 rated only in proportion as these motions were destroyed 

 by friction. We do not know if this would last for hours, 

 or days, or weeks. The fragments, therefore, projected 

 in the first instant with planetary velocity might escape 

 without any development of heat. I do not even think it 

 impossible that a stone, or swarm of stones. Hying 

 through lofty strata of the atmosphere of a world might 

 catch up and sweep along a quantity of air containing 

 unburnt germs. 



I have already said that I should not yet be willing to 

 put forth all these possibilities as probabilities. They 

 are only questions the existence and range of which must 

 be kept in \iew, so that if opportunity offers they may be 

 solved by actual observation or by inferences from such. 



Mr. ZoUner then ascends to the two following propo- 

 sitions : — 



" That scientific investigators in the present day 



attach such extraordinary importance to iiuliutk'c jiroof 

 of generaiio cequivoca, is the clearest mark of their lack 

 of famUiarity with the first principles of the theory of 

 knowing." 



And again : — 



" In like manner the hypothesis of gcneratio crqitivoca 

 expresses . . . nothing else than the condition for the 

 conceivableness of nature in accordance with the law of 

 causality." 



Here we have the genuine metaphysician. In view of 

 a presumed necessity of thought, he looks down with an 

 air of superiority on those who labour to investigate the 

 facts. Has it already been forgotten how much mischief 

 this procedure wi"ought in earlier stages of the deve- 

 lopment of the sciences ? And what is the logical basis 

 of this lofty standpoint ? The correct alternative is 

 clearly this : — 



" Either organic life began to exist at some particular 

 time, or it has existed from all eternity." 



Mr. ZoUner simply omits the second of these alterna- 

 tives, or thinks that he has set it aside by a passing 

 reference brought in shortly before to certain physical 

 considerations which are not in the least decisive. Ac- 

 cordingly his conclusion, which affirms the first of the 

 alternatives above stated, is either not proved at all, or 

 proved only by the aid of a minor resting on physical 

 arguments (and, for that matter, inadequate physical 

 arguments). The conclusion, therefore, is not in any 

 sense, as Mr. ZoUner believes, a proposition of logical 

 necessity, but at most an uncertain inference from physi- 

 cal considerations. 



This is what Mr. ZoUner has to object to the authors 

 of this handbook in the sphere of scientific questions.* 

 Mr. ZoUner's book contains a great number of other 

 accusations of precisely the same value directed against 

 other scientific investigators, with the same confidence 

 in his own infaUibility and the same rash haste in pass- 

 ing judgment on the intellectual and moral qualities of 

 his antagonist. Another opportunity will present itself 

 for the discussion of another part of these cases. If I 

 may draw by anticipation a moral interesting to us in the 

 present connection, I would say that no theoretical argu- 

 ments can present to the attentive and judicious reader a 

 stronger and more eloquent justification of the strict dis- 

 cipline of the inductive method, the loyal adhesion to 

 facts which has made science great, than is supplied by 

 the practical example of the consequences of the oppo- 

 site, would-be deductive, or speculative method given in 

 ZoUner's book; and this all the more that l\Ir. ZoUner 

 is beyond question a man of talent and knowledge, who 

 did most promising work before he fell into metaphysics, 

 and even now shows acuteness and the faculty of inven- 

 tion whenever he is limited to the field of the actual, e.g. 

 in the construction of optical instruments and the devising 

 of optical methods. 



NEW ZEALAND PLANTS SUITABLE FOR 



PA PER- MA KING 

 npHE utilisation of waste materials for paper-making is- 

 •^ a subject upon which a great deal has been said and 

 still remains to be said and done. In every country waste 

 vegetable matter which contains fibre in anything like 

 suitable proportions is sure to attract much attention.. 

 The subject has been handled in various works, directly 

 or indirectly, in this country as well as on the Continent ;. 

 and with regard to Australian plants suitable for paper- 

 making, Baron Mueller, of Melbourne, issued a lengthy 

 treatise in connection with a series of specimens of paper 

 actually made from the plants enumerated and exhibited 

 in the Paris Exhibition of 1S67. We have now before- 

 us a paper by Mr. T. Kirk, F.L.S., of Wellington, on^ 



* In the region of personal questions, and witli reference to the claim of 

 priority as to the principles of spectral analysis made by Sir W. Thomson 

 for Mr. Stokes against ]Mr. KirchhotT, I must side with the latter, fully 

 agreeing with the reasons which he has himself brought fonvard. 



