PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 719 



discoveries, and we must not be surprised when we receive an 

 avalanche of discoveries and inventions in all parts of arts and 

 sciences. We may truly say that great revelations are dawning, 

 and that the old saying -'thus far shalt thou go, and no farther" 

 has become obsolete. The progress of the human mind in useful 

 knowledge appears to know no bounds. Notwithstanding all this, 

 we see that the 2:oal of knowledoe is and remains at an iulinite 

 distance, and the remarkable saying of the old German professor, 

 Wolft, is more and more verified, which was: "All that we possi- 

 bly may learn, is only an infinitely small portion of what there is 

 left to be known." 



Hippocrates, the father of medicine and founder of the true medi- 

 cal philosophy, commences his glorious and remarkable book with 

 the well-known sentence, ^^Ars Ionga,vila bi'evis^^ — the art is long, 

 life is short. But as transitory as individual life is, compared with 

 the existence of the human race, (which it is now proved has existed 

 at least 200,000 years on our planet,) just as transitory is the 

 existence of the human race, compared with the existence of our 

 globe, and again, just as transitory is the existence of our earth, 

 as a globe, compared with the existence of what v/e call the uni- 

 verse, which itself is 1)ut a transitory outgrowth of the eternal 

 forces which animate the eternal matter. 



Astronomy, aided with the powerful modern telescopes, reveals 

 us the history of the formation of the starry and planetary sys- 

 tems. Geology, aided with all the light of physics, chemistry 

 and natural history, reveals to us what properly should be called 

 the natural history of our earth. Both agree that the most stu- 

 j)endous changes have gone on, as well in the motion of our globe 

 as in its physical condition; changes which we now commence to 

 see, that never took place by paroxismal action, spasmodically, 

 but slowly, after well-fixed natural laws of continuity, and we 

 must come to the conclusion that, as the different conditions 

 through which our earth passed were transitor}^, so its present 

 condition is transitory, notwithstanding it may for us short-sighted 

 men appear to be of the most perfect stability. 



But the question raised, and which gave some apparent ground 

 to the idea of perfect stability, was this: Were not all these changes 

 preparatory operations necessary to prepare the earth to its pres- 

 ent perfect state, which being once reached, the stability was 

 secured and strictly maintained ? As far as facts were known 

 about a century ago, this appeared really to be the case; the timo 



