MECHANICS AND USEFUL ARTS. 25 



may presume to set limits? Already natural processes can be more econom- 

 ically replaced by artificial ones in the formation of a few organic com- 

 pounds, the " valerianic acid," for example. It is impossible to foresee the 

 extent to which Chemistry may not ultimately, in the production of things 

 needful, supersede the present vital agencies of nature, "by laying under 

 contribution the accumulated forces of past ages, which would thus enable 

 us to obtain in a small manufactory, and in a few days, effects which can be 

 realized from present natural agencies only when they are exerted upon vast 

 areas of land, and through considerable periods of time." Since Niepcc, 

 Herschel, Fox Talbot, and Daguerre, laid the foundations of Photography, 

 year by year some improvement is made, some advance achieved, in this 

 most subtle application of combined discoveries in Photicity, Electricity, 

 Chemistry, and Magnetism. Last year M. Poitevin's production of plates 

 in relief, for the purpose of engraving by the action of light alone, was 

 cited as the latest marvel of Photography. This year has Avitncssed photo- 

 graphic printing in carbon by M. Pretsch. Prof. Owen continued by allud- 

 ing to the application of Photography for obtaining views of the moon, of 

 the planets, of scientific and other phenomena. After referring to the dis- 

 coveries in Electro-magnetism, the lecturer continued : Remote as such pro- 

 found conceptions and subtle trains of thought seem to be from the needs 

 of everyday life, the most astounding of the practical augmentation of man's 

 power has sprung out of them. Xothing might seem less promising of 

 profit than Oersted's painfully-pursued experiments, with his little magnets, 

 voltaic pile, and bits of copper wire. Yet out of these has sprung the elec- 

 tric telegraph ! Oersted himself saw such an application of his convertibility 

 of electricity into magnetism, and made arrangements for testing that appli- 

 cation to the instantaneous communication of signs through distances of a 

 few miles. The resources of inventive genius have made it practicable for 

 all distances; as we have lately seen in the submergence and working of the 

 electro-magnetic cord connecting the Old and the ISTew World. More re- 

 mains to be done before the far-stretching engine can be got into working 

 order; but the capital fact, viz., the practicability of bringing America into 

 electrical communication with Europe has been demonstrated ; consequently, 

 a like power of instantaneous interchange of thought between the civilized 

 inhabitants of every part of the globe becomes only a question of time. 

 The powers and benefits thence to ensue for the human race can be but 

 dimly and inadequately foreseen. After referring to the labors of Kay, Lin- 

 na'iis, .Tussieu, BitfFon, and Cuvier, he said: To perfect the natural system 

 of plants has been the great aim of botanists since Jussieu. To obtain the 

 same true insight into the relations of animals has stimulated the labors of 

 zoologists since the writings of Cuvier. To that great man appertains the 

 merit of having systematically pursued and applied anatomical researches 

 to the discovery of the true system of distribution o the animal kingdom; 

 nor, until the Cuvierian amount of zootomical science had been gained, 

 could the value and importance of Aristotle's " History of Animals " be ap- 

 preciated. There is no similar instance, in the history of Science, of the 

 well-lit torch gradually growing dimmer and smouldering through so many 

 generations and centuries before it was again fanned into brightness, and a 

 clear view regained, both of the extent of ancient discovery, and of the 

 true course to be pursued by modern research. Rapid and right has been 

 the progiv.-s of Zoology si-ir-e that resumption. X<>t only has the structure, 

 of the aiiiuial been in \ebiigated, even to the minute characteristic., of 



3 



