INTRODUCTION. 7 



boundary which connects the metaphysical with the physical, 

 and leads us into another and higher sphere of ideas. The 

 image of the immeasurable, the boundless, and the eternal, is 

 associated with a power which excites within us a more earn- 

 est and solemn tone of feeling, and which, like the impres- 

 sion of all that is spiritually great and morally exalted, is not 

 devoid of emotion. 



The effect which the aspect of extraordinary celestial phe- 

 nomena so generally and simultaneously exerts upon entire 

 masses of people, bears witness to the influence of such an 

 association of feelings. The impression produced in excita- 

 ble minds by the mere aspect of the starry vault of heaven 

 is increased by profounder knowledge, and by the use of those 

 means which man has invented to augment his powers of vi- 

 sion, and at the same time enlarge the horizon of his observ- 

 ation. A certain impression of peace and calmness blends 

 with the impression of the incomprehensible in the universe, 

 and is awakened by the mental conception of normal regu- 

 larity and order. It takes from the unfathomable depths of 

 space and time those features of terror which an excited im- 

 agination is apt to ascribe to them. In all latitudes man, 

 in the simple natural susceptibihty of his mind, prizes '* the 

 calm stillness of a starlit summer night." 



Although magnitude of space. and mass appertains more 

 especially to the sidereal portion of cosmical delineation, and 

 the eye is the only organ of cosmical contemplation, our tel- 

 luric sphere has, on the other hand, the preponderating ad- 

 vantage of presenting us with a greater and a scientifically 

 distinguishable diversity in the numerous elementary bodies 

 of which it is composed. All our senses bring us in contact 

 with terrestrial nature ; and while astronomy, which, as the 

 knowledge of moving luminous celestial bodies is most acces- 

 sible to mathematical treatment, has been the means of in- 

 creasing in the most marvelous manner the splendor of the 

 higher forms of analysis, and has equally enlarged the lim- 

 its of the extensive domain of optics, our earthly sphere, on 

 the other hand, by its heterogeneity of elements, and by the 

 complicated play of the expressions of force inherent" in 

 matter, has formed a basis for chemistry, and for all those 

 branches of physical science which 'treat of phenomena 

 that have not as yet been found to be connected with vibra- 

 tions generating heat and light. Each sphere has, there- 

 fore, in accordance with the nature of the problems which 

 it presents to our investigation, exerted a different influence 



