607 



SCIENTIFIC SIDE-LIGHTS 



Science 



3001. SCIENCE OVERCOMES DIF- 

 FICULTIES Color-photography. It has 

 long been the dream of photographers to dis- 

 cover some mode of obtaining pictures which 

 shall reproduce all the colors of Nature 

 without the intervention of the artist's 

 manipulation. This was seen to be exceed- 

 ingly difficult, if not impossible, because the 

 chemical action of colored light has no 

 power to produce pigments of the same color 

 as the light itself, without which a photo- 

 graph in natural colors would seem to be 

 impossible. Nevertheless, the problem has 

 been solved, but in a totally different man- 

 ner ; that is, by the principle of " interfer- 

 ence," instead of by that of chemical action. 

 This principle was discovered by Newton, 

 and is exemplified in the colors of the soap- 

 bubble, and in those of mother-of-pearl and 

 other iridescent objects. It depends on the 

 fact that the differently colored rays are of 

 different wave-lengths, and the waves re- 

 flected from two surfaces half a wave-length 

 apart neutralize each other and leave the 

 remainder of the light colored. If, there- 

 fore, each differently colored ray of light 

 can be made to produce a corresponding 

 minute wave-structure in a photographic 

 film, then each part of the film will reflect 

 only light of that particular wave-length, 

 and therefore of that particular color, that 

 produced it. This has actually been done by 

 Professor Lippmann, of Paris, who pub- 

 lished his method in 1891 ; and in a lecture 

 before the Royal Society in April, 1896, he 

 fully described it and exhibited many beau- 

 tiful specimens. WALLACE The Wonderful 

 Century, ch. 5, p. 36. (D. M. & Co., 1899.) 



3002. SCIENCE PERSONIFIES FOR- 

 CES Laws Invested with Attributes of Mind. 

 The universal prevalence of this idea of 

 purpose in Nature is indicated by the irre- 

 sistible tendency which we observe in the 

 language of science to personify the forces, 

 and the combinations of force by which all 

 natural phenomena are produced. It is a 

 great injustice to scientific men too often 

 committed to suspect them of unwilling- 

 ness to accept the idea of a personal Creator 

 merely because they try to keep separate the 

 language of science from the language of 

 theology. But it is curious to observe how 

 this endeavor constantly breaks down how 

 impossible it is in describing physical phe- 

 nomena to avoid the phraseology which 

 identifies them with the phenomena of mind, 

 and is molded on our own conscious person- 

 ality and will. It is impossible to avoid this 

 language simply because no other language 

 conveys the impression which innumerable 

 structures leave upon the mind. Take, for 

 example, the word "contrivance." How 

 could science do without it? How could the 

 great subject of animal mechanics be dealt 

 with scientifically without continual refer- 

 ence to law ^ as that by which, and through 

 which, special organs are formed for the 

 doing of special work? What is the very 



definition of a machine? Machines do not 

 increase force, they only adjust it. The very 

 idea and essence of a machine is that it is a 

 contrivance for the distribution of force 

 with a view to its bearing on special pur- 

 poses. A man's arm is a machine in which 

 the law of leverage is supplied to the vital 

 force for the purposes of prehension. . . . 

 Anatomy supplies an infinite number of 

 similar examples. It is impossible to describe 

 or explain the facts we meet with in this 

 or in any other branch of science without 

 investing the " laws " of Nature with some- 

 thing of that personality which they do 

 actually reflect, or without conceiving of 

 them as partaking of those attributes of 

 mind which we everywhere recognize in their 

 working and results. ARGYLL Reign of Law, 

 ch. 2, p. 54. (Burt.) 



3OO3. SCIENCE, PHYSICAL VS. 



MENTAL Individuality of Consciousness. 

 The phenomena of the external world are 

 so palpable and so easily described that the 

 experience of one observer suffices to render 

 the facts he has witnessed intelligible and 

 probable to all. The phenomena of the in- 

 ternal world, on the contrary, are not capa- 

 ble of being thus described; all that the 

 prior observer can do is to enable others 

 to repeat his experience. In the science of 

 mind we can neither understand nor be con- 

 vinced of anything at second hand. Here 

 testimony can impose no belief, and instruc- 

 tion is only instruction as it enables us to 

 teach ourselves. A fact of consciousness, 

 however accurately observed, however clearly 

 described, and however great maybe our con- 

 fidence in the observer, is for us as zero, until 

 we have observed and recognized it ourselves. 

 Till that be done we cannot realize its possi- 

 bility, far less admit its truth. Thus it is 

 that, in the philosophy of mind, instruction 

 can do little more than point out the position 

 in which the pupil ought to place himself, in 

 order to verify, by his own experience, the 

 facts which his instructor proposes to him 

 as true. HAMILTON Metaphysics, lect. 1, p. 

 11. (G. & L., 1859.) 



3OO4 SCIENCE, PRACTICAL A 



Message of, to Man about Himself. What 

 science has to say about himself is of tran- 

 scendent interest to man, and the practical 

 bearings of this theme are coming to be 

 more vital than any on the field of knowl- 

 edge. DRUMMOND Ascent of Man, pref., p. 

 5. (J. P., 1900.) 



3005. 



Utility Sought and 



Attained Treatment of Soil to Avoid Frost. 

 From the fact of the great heat-absorp- 

 tion by dark soils, the increased loss of 

 heat by night necessarily follows. In such 

 districts the occurrence of night frosts is 

 promoted in a high degree, a result that is 

 of the greatest importance to vegetation. 

 Experiments on a great scale have been 

 made in the black, low grounds of North 

 Germany for instance, in Dromling, the 



