A NEEDED RECONSTRUCTION OF TEE NEBULAR EYPO TRESIS. 309 



the golden rays of all the suns which people in- 

 finity." But the very scene which suggested 

 these ideas should have taught another lesson. 

 Not every region of earth is inhabited, not every 

 inhabited region is a Rome, or an Athens, or a 

 Taris, or a London. While some great nation 

 or city is enjoying the fullness of its vigor, others 

 are perishing or have long since passed away, 

 others are as yet unknown, or but begin their 

 existence. So may it well be, so must it be if 

 analogy is our guide; so is it if our observations 

 can be trusted, with other planets than this 

 earth, with other systems than our sun's. As 

 each orb occupies but the minutest portion of 

 the infinity of space, so is the lifetime of each 



but a wavelet in the ocean of eternity. Two 

 wavelets, or many, may run side by side upon 

 an endless sea, and so may the lifetime of our 

 earth synchronize with life upon another world, 

 or many others. But for each wave that thus 

 runs beside the wave of life on which our lot is 

 cast, a myriad — nay, ten million million others — 

 are far removed from ours, lie even beyond the 

 horizon bounding what we call time. The uni- 

 verse, as we know it, the region of space to 

 which our most powerful telescopes penetrate, is 

 not more utterly lost in the true universe of infinity 

 than is the range of time, past, present, and to 

 come, over which our researches extend, amid the 

 infinities of time eternal. — Corn/till Magazine. 



A NEEDED EECONSTEUCTION OF 



POTHESLS.' 



THE NEBULAE HY- 



Br CAEL DU PEEL. 

 " Si les phenomenes ne sont pas enchaincs les uns aux autres, il n'y a pas de philosophic." 2 — Diderot. 



EVERY sense-impression takes a certain time 

 to reach the consciousness, the length of 

 time varying with the force of the impression and 

 the sensibility of the individual. If with the 

 physiologists we take the mean length of this in- 

 terval to be one-sixth of a second, it becomes 

 evident that in very rapidly reading print there 

 is not time sufficient for each letter of every sepa- 

 rate word to make its due impression. Were 

 this not so, the task of discovering printers' errors 

 would be far easier than it really is, even when 

 we peruse a printed page with that one object in 

 view. Since, however, we apprehend the mean- 

 ing of what is read, fast reading must be more 

 or less guessing, inasmuch as we fill in from our 

 own resources the missing impressions, and from 

 a few letters infer the whole word. Reading, 

 therefore, is more or less a synthetic function 

 of the human mind, and the greater one's power 

 of synthesis, the greater (all other things being 

 equal) will be his power of reading rapidly. Un- 

 doubtedly we are aided here by the fact that 

 all the words in a sentence cohere to produce an 

 intelligible impression, and under such circum- 

 stances we infer a word much more readily than 

 we could if it stood alone. 



1 Translated from the German by J. Fitzgerald, A. M. 



2 " Unless phenomena are linked together, there is no 

 philosophy." 



24 



In reading the book of Nature we exercise a 

 like synthetic function of the mind. Inasmuch 

 as we are ignorant of the causal relations sub- 

 sisting between multitudes of natural phenomena, 

 this book is for us, as it were, resolved into its 

 words and letters ; indeed, no small portion of 

 the contents of the book is altogether unknown 

 to us. It is for the investigator of Nature, in the 

 narrower sense of the term, to analyze and ex- 

 plore with all possible minuteness individual phe- 

 nomena ; but he takes rank among philosophers 

 when he goes further and strives to class together 

 those phenomena which are united by the invisi- 

 ble bond of the law of causality. Herein he must 

 depend on his faculty of synthesis for the power 

 of detecting the proximate or remote, the direct 

 or collateral relations of phenomena. Often, 

 however, this can only be done by filling up the 

 gaps in our knowledge, just as in reading we fill 

 up the gaps in the series of sense-impressions, and 

 by inferring the existence of phenomena that we 

 have never seen. Thus do we construct words, 

 sentences, chapters, of the book of Nature out of 

 the defective series of phenomena given us in ex- 

 perience. 



In a greater or less degree all branches of 

 natural science have already entered on that 

 phase wherein further development depends on 

 the synthetic faculty, and the human mind will 



