317 



SCIENTIFIC SIDE-LIGHTS 



Ice-clouds 

 Identification 



spending complication in result. Like many 

 other laws of the same class, it was discov- 

 ered, not by looking outward, but by looking 

 inward; not by observing, but by thinking. 

 ARGYLL Reign of. Law, ch. 2, p. 65. 

 (Burt.) 



1545. IDEA OF MATHEMATICIAN 

 REALIZED IN CRYSTAL Theory of Undu- 

 lations Verified. Effects [of refraction] 

 which, without a theoretic clue, would leave 

 the human mind in a jungle of phenomena 

 without harmony or relation, were organic- 

 ally connected by the theory of undulation. 



The theory was applied and verified in all 

 directions, Airy being especially conspicuous 

 for the severity and collusiveness of his 

 proofs. The most remarkable verification 

 fell to the lot of the late Sir William Ham- 

 ilton, of Dublin, who, taking up the theory 

 where Fresnel had left it, arrived at the 

 conclusion that at four special points of 

 the " wave-surface " in double-refracting 

 crystals the ray was divided, not into two 

 parts, but into an infinite number of parts, 

 forming at these points a continuous conical 

 envelope instead of two images. No human 

 eye had ever seen this envelope when Sir 

 William Hamilton inferred its existence. 

 He asked Dr. Lloyd to test experimentally 

 the truth of his theoretic conclusion. Lloyd, 

 taking a crystal of aragonite, and following 

 with the most scrupulous exactness the in- 

 dications of theory, cutting the crystal 

 where theory said it ought to be cut, ob- 

 serving it where theory said it ought to 

 be observed, discovered the luminous envel- 

 ope which had previously been a mere idea 

 in the mind of the mathematician. TYN- 

 DALL Lectures on Light, p. 212. (A., 1898.) 



1546. IDEAS, ABSTRACT, OF SLOW 

 GROWTH Not To Be Attributed to Primitive 

 Man Conception of Energy or Force Late 

 and Difficult Powers of Nature Regarded 

 as Energies of Persons. When, again, we 

 are told by Sanskrit scholars that the ear- 

 liest religious conceptions of the Aryan race, 

 as exhibited in the Veda, were pantheistic, 

 and that the gods they worshiped were 

 " deifications " of the forces or powers of 

 Nature, we are to remember that this is an 

 interpretation, and not a fact. It is an in- 

 terpretation, too, which assumes the famili- 

 arity of the human mind, in the ages of its 

 infancy, with one of the most doubtful and 

 difficult conceptions of modern science 

 namely, the abstract conception of energy 

 or force as an inseparable attribute of mat- 

 ter. ^ The only fact, divested of all precon- 

 ceptions, which these scholars have really 

 ascertained is that in compositions which 

 are confessedly poetical the energies of Na- 

 ture were habitually addressed as the ener- 

 gies of personal or living beings. But this 

 fact does not in the least involve the sup- 

 position that the energies of Nature which 

 are thus addressed had, at some still earlier 

 epoch, been regarded under the aspect of 

 material forces, and had afterwards come 



to be personified; nor does it in the least 

 involve the other supposition that, when 

 so personified, they were really regarded as 

 so many different beings absolutely sepa- 

 rate and distinct from each other. Both 

 of these suppositions may indeed be matter 

 of argument, but neither of them can be 

 legitimately assumed. ARGYLL Unity of 

 Nature, ch. 12, p. 303. (Burt.) 



1547. IDEAS NOT DEJECTS, BUT 



PROCESSES Comparison of Thinking to Wri- 

 ting. As a matter of fact, ideas, like all 

 other mental experiences, are not objects, 

 but processes, occurrences. The idea which 

 we refer back to a previous one, when we 

 apprehend it as similar to that, is no more 

 the earlier idea itself than the word which 

 we write or the picture which we draw is 

 identical with the same word which we 

 wrote previously or the similar drawing 

 which we made some time ago. Indeed, you 

 will see, if you consider the complex con- 

 ditions under which our inner experience 

 arises, that nothing like the same degree 

 of similarity between the earlier and the 

 later product can be expected here as may 

 be found under certain circumstances in the 

 field of external actions like writing and 

 drawing. The circumstance that new proc- 

 esses exhibit relations and similarity to 

 others previously existing can no more prove 

 the continued existence of the idea as such 

 than it can be inferred from the similarity 

 of the movement of the pen in writing a 

 definite word now to that involved on a for- 

 mer occasion, that this movement has con- 

 tinued to exist in an invisible form from 

 the time it was first made, and has simply 

 become visible again when we have written 

 the word anew. WUNDT Psychology, lect. 

 16, p. 236. (Son. & Co., 1896.) 



1548. IDENTIFICATION OFTEN FAL- 

 LACIOUS Witness Sees the Expected Forma 

 Recognized in " Materializing Seances." 

 Testimony to personal identity is prover- 

 bially fallacious for similar reasons [viz. : il- 

 lusion through preconception]. A man has 

 witnessed a rapid crime or accident, and 

 carries away his mental image. Later he 

 is confronted by a prisoner whom he forth- 

 with perceives in the light of that image, 

 and recognizes, or " identifies," as a par- 

 ticipant, altho he may never have been 

 near the spot. Similarly at the so-called 

 " materializing stances " which fraudulent 

 mediums give: in a dark room a man sees 

 a gauze-robed figure who in a whisper tells 

 him she is the spirit of his sister, mother, 

 wife, or child, and falls upon his neck. The 

 darkness, the previous forms, and the ex- 

 pectancy have so filled his mind with pre- 

 monitory images that it is no wonder he 

 perceives what is suggested. These fraudu- 

 lent " stances " would furnish most precious 

 documents to the psychology of perception, 

 if they could only be satisfactorily inquired 

 into. JAMES Psychology, vol. ii, ch. 19, p. 

 97. (H. H. & Co., 1899.) 



