Jan. 30, 1890] 



NATURE 



295 



of ' ' use " — and the tendency — or the disposition — or the instinct — 

 to use ? The answer may be, and perhaps always must be, that 

 the possibility of each new use, and the disposition to it, has 

 been acquired from the evolution of elements inherent in the 

 germ. 



The next specimen of pure scientific reasoning which I find 

 in Mr, Dyer's letter is involved in his rebuke to me for having 

 made an assertion in support of which I have produced no 

 " definite observed evidence." That assertion he correctly 

 quotes thus : — " All organs do actually pass through rudi- 

 mentary stages in which actual use is impossible." He chal- 

 lenges me for proof. I return the challenge, and summon 

 Mr. Dyer to produce one single instance of any animal which 

 does NOT pass through such stages. It is the universal law of 

 all organic beings. In some germ — in some bud — in some egg 

 — in some womb, every living thing begins to grow. Moreover, 

 what is true of it as a whole, is true of all its parts. All its 

 organs — be they few and simple, or many and complex — pass 

 through stages of incipience, of impotence — of divorce from 

 even the possibility of actual and present use. It is truly an 

 astonishing circumstance that any scientific man should ask for 

 any proof of this. It is a signal illustration of the power of 

 neglected elements in reasoning — of the familiar becoming the 

 practically unknown, because it is the unconsidered. 



Possibly, Mr. Dyer may say that he did not understand me to 

 make the assertion of each individual organism. But this is a 

 distinction without a difference. If the Darwinian theory be 

 true, there has never been any other origin for species than the 

 origin of a few first germs — developed ever since by the pro- 

 cesses of ordinary generation, through a succession of individuals. 

 The well-known generalization of Darwinian embryologists is that 

 the foetal development of the individual organism is the type and 

 repetition of the development of species in the womb of time. 

 In the doctrine of " prophetic germs," which he quotes as mine, 

 nothing is mine except, perhaps, the adoption of the words. It 

 is the embodiment, in what I hold to be accurate and appro- 

 priate language, of the most familiar facts in nature, and of the 

 intellectual conceptions which are their necessary counterpart in 

 mind. 



ITiere is one consequence necessarily following from this con- 

 ception, which is seldom thought of and never fully accepted or 

 recognized; and that is, that, if every organism has been deve- 

 loped from older organisms by very slow and gradual and 

 minute changes through unnumbered ages, there must have been 

 a constant succession of new organs coming on, along with an 

 equally constant succession of other organs passing off. I see 

 no escape from this conclusion. Yet if it be true, nothing can 

 be more unreasonable than to wonder at the occurrence of struc- 

 tures which are divorced from actual use, and which are variously 

 called "rudimentary," or "aborted." The common interpreta- 

 tion always is that they are the inherited remains of structures 

 which have been once in full use, and have been lost by the 

 atrophy of disuse. This may or may not be true, according to 

 special facts in each case. But that there has always been in 

 time past a series of incipient structures on the rise for actual 

 use in future generations of development is a necessary conse- 

 quence of the Darwinian hypothesis, and indeed of all other 

 iorms of pure evolutionism. The only escape from it is the sup- 

 position that special organs may have arisen suddenly — may have 

 advanced rapidly into functional use — as rapidly as a caterpillar 

 rushes into the structure of a butterfly, after a short interval of 

 inactivity or sleep. 



This is possible — this is at least conceivable. Nay more, this 

 may have been the process by which new species have been 

 introduced. But this is not Darwinism. The occasional intro- 

 duction of new germs, with new potentialities, and the "hurry- 

 ing up " of these through rapid stages of development, or of 

 hatching, is an idea which, if I remember right, did not escape 

 the speculative glance of Darwin. But it was too incongruous 

 to be easily assimilated with his special formulae, and so his fine 

 eye glanced off it again, after only a momentary look ; and at a 

 later date he was so biassed in favour of the mechanics of for- 

 tuitous variation that he came to regard the very idea of develop- 

 ment being guided towards any use yet lying wholly in the 

 future as incompatible with his theory, and indeed destructive 

 of it. 



Mr, Dyer says that there was nothing in my last letter " which 

 has not been worn threadbare by discussion." If so, it seems a 

 pity that Mr. Dyer should have interposed in a discussion which 

 he thinks exhausted. This impression may account for the 



poverty of the contribution made by an able man to a subject 

 which is perhaps the most difficult, the most interesting, and 

 the most far-reaching which can engage the human under- 

 standing. .\rgyll. 

 Inveraray, January 19, 



Multiple Resonance obtained with Hertz's Vibrators. 



While Mr. Trouton and I were carrying out some experi ' 

 ments to try and drive an independent current through the arc 

 formed when a spark passes in a Hertzian resonating receiver, 

 we succeeded to some extent in doing so, but obtained an un- 

 expected result which may be of service to others working upon 

 this matter. We found that if the two sides of the receiver be 

 connected with a delicate galvanometer, it is affected whenever 

 a spark passes. It is not so easy to get sparks to pass when the 

 galvanometer is so connected as when the receiver is insulated ; 

 but whenever a spark passes, the galvanometer — a 7000-ohm 

 Cambridge Scientific Instrument Company's pattern — is deflected 

 through several degrees and often off the scale. It is not very 

 easy to see how the action takes place, because one would 

 imagine that an electro-dynamometer would be required. The 

 current is reversed along with the reversal of the primary induc- 

 tion, and seems to be connected with the direction of the electro- 

 magnetic impulse that first breaks down the air-space in the 

 receiver : an explanation founded upon this consideration ex- 

 plains the facts so far, but further investigation is required to 

 fully confirm it. We have found this method of observing the 

 Hertzian phenomena, which we have worked successfully with 

 an apparatus giving a wave-length of o"6 metre, much more 

 satisfactory than the method founded on utilizing the conductivity 

 of the spark as a path to drive an independent current either 

 across or along. Some experiments in a vacuum tube, however, 

 showed that this method is capable of extension. We found it 

 also more satisfactory than a bolometer method, which, however, 

 worked fairly well. For this we interposed, instead of the spark- 

 gap, a very fine wire, which was made into one of the arms of a 

 Wheatstone's bridge. The great desideratum was a very fine 

 wire, and we intend trying silvered quartz fibres if we can obtain 

 them, and lead drawn inside glass, &c., our heai^s having been 

 broken trying to use that brittle beauty, Wollaston wire. 



Any of these methods, in which your observing apparatus, the 

 galvanometer, can be at a distance from the receiver, is more 

 manageable than ones like that described by Mr. Gregory, in 

 which the receiver is itself also the observing apparatus. We 

 exhibited our method of observing the occurrence of spark by con- 

 necting the ends of the spark-gap with a delicate galvanometer 

 at the meeting of the Dublin University Experimental Science 

 Association last November. Geo. Fras. Fitzgerald. 



January 25, 



As I see from a notice of the proceedings of the Academy 

 of Sciences, Paris, in last week's Nature (p. 287), that MM, 

 Edouard Sarasin and Lucien de la Rive have observed the fact 

 that " multiple resonance " can be obtained by using different 

 sized resonators with a Hertzian "vibrator,"! adjoin the fol- 

 lowing short account of experiments of a somewhat different 

 character made during last autumn, which have led to the same 

 results, and which were brought before the notice of the Dublin 

 University Experimental Association last November. Since 

 then I have learnt what these experimenters also seem not to 

 have known — that some of Hertz's earlier experiments were more 

 especially concerned with this very fact. 



First, it was found that the wave-length in the Hertzian ex- 

 periment of loop and nodes formed by reflection from a large 

 metallic sheet had altered since the apparatus had been last 

 used some months previously. This was attributed at first to 

 something in the "vibrator," such as the width of the spark- 

 gap ; but ultimately, on remembering how an accident had 

 necessitated a new resonator being made, the cause was recog- 

 nized — namely, that it was not exactly the same size as the 

 previous one ; and when several resonators of different sizes 

 were made, they were found to give the node at different distances 

 from the reflecting sheet. The intensity of the sparking with 

 which these were affected increased with their size up to a certain 

 point, and then diminished. So that it seems as if a "vibrator" 

 did not send out a " line spectrum," so to speak, but sends out 

 a "band spectrum," the centre of which is the brightest The 

 period, then, of a "vibrator" is that belonging to the centre of 

 this "band." 



