iM COSMOS. 



knowledge. 1 take pleasure in persuading myself that scien- 

 tific subjects may be treated of in language at once dignified, 

 grave, and animated, and that those who are restricted with- 

 in the circumscribed limits of ordinary life, and have long re- 

 mained strangers to an intimate communion with nature, 

 may thus have opened to them one of the richest sources of 

 enjoyment, by which the mind is invigorated by the acquisi- 

 tion of new ideas. Communion with nature awakens within 

 us perceptive faculties that had long lain dormant ; and we 

 thus comprehend at a single glance the influence exercised by 

 physical discoveries on the enlargement of the sphere of intel- 

 lect, and perceive how a judicious application of mechanics, 

 chemistry, and other sciences may be made conducive to na- 

 tional prosperity. 



A more accurate knowledge of the connection of physical 

 phenomena will also tend to remove the prevalent error that • 

 all branches of natural science are not equally important in 

 relation to general cultivation and industrial progress. An 

 arbitrary distinction is frequently made between the various 

 degrees of importance appertaining to mathematical sciences, 

 to the study of organized beings, the knowledge of electro- 

 magnetism, and investigations of the general properties of mat- 

 ter in its different conditions of molecular aggregation ; and it 

 is not uncommon presumptuously to affix a supposed stigma 

 upon researches of this nature, by terming them " purely the- 

 oretical/' forgetting, although the fact has been long attested, 

 that in the observation of a phenomenon, which at first sight 

 appears to be wholly isolated, may be concealed the germ of a 

 great discovery. When Aloysio Galvani first stimulated the 

 nervous fiber by the accidental contact of two heterogeneous 

 metals, his cotemporaries could never have anticipated that 

 the action of the voltaic pile would discover to us, in the al- 

 kalies, metals of a silvery luster, so light as to swim on wa- 

 ter, and eminently inflammable ; or that it would become a 

 powerful instrument of chemical analysis, and at the same 

 time a thermoscope and a magnet. When Huygens first ob- 

 served, in 1678, the phenomenon of the polarization of light, 

 exhibited in the difference between the two rays into which 

 a pencil of light divides itself in passing through a doubly 

 refracting crystal, it could not have been foreseen that, a 

 century and a half later, the great philosopher. Arago would, 

 by his discovery of chromatic polarization, be led to discern, 

 by means of a small fragment of Iceland spar, whether solar 

 light emanates from a solid body or a gaseous covering, ox 



