8 VIEWS OF THE MICROSCOPIC WORLD. 



the successive realms of the invisible, exploring onward towards the inner shrine 

 of nature ; that new scenes of beauty would continually unfold, and new fields 

 of Omniscient display would be constantly revealing, that God was still before us 

 in his creative energy, that we saw " but the hidings of his power." And as we 

 traced our step| back to the visible through all the glorious realms that had been 

 brought to light, we should feel the truth, that this outer world is but the casket 

 in which the riches of creation are enshrined. 



THE MICROSCOPE. 



Before we proceed to describe the wonders and beauties revealed by the 

 Microscope, it appears not only desirable but highly important, that the instru- 

 ment itself should be well understood, and the optical principles involved in its 

 construction firmly fixed in the mind. And for the obvious reason, that an intel- 

 ligent mind not only wishes to be acquainted with results, but also with the 

 means and processes by which those results are obtained ; for if it is possessed 

 of the results only, it is dependent for the truth or falsity of its information sim- 

 ply upon the credit due to its instructor for honesty and accuracy ; but when each 

 step from the beginning to the end is tested by the judgment, and everything 

 rejected that bears not the stamp of truth, knowledge then becomes doubly valua- 

 ble, and the conclusions that are presented are then received not with a lukewarm 

 and faint assent, but are at once embraced in full and undoubted confidence. 



In the subject before us it is peculiarly requisite that the reader should know 

 the capacities of the instrument, which introduces him into such new and surprising 

 scenes amid the fields of creation; inasmuch as the objects with which it deals 

 are so minute, that although their dimensions can be ascertained with very great 

 precision, yet a person unacquainted with the power of the Microscope would be 

 much disposed to receive the actual measurements of objects with some dis- 

 trust, regarding them only as broad approximations towards the truth ; ingenious 

 indeed, but mere guesses at the best. 



SINGLE MICROSCOPE. An object is rendered visible by rays of light, which 

 emanating from points on its surface, are received by the eye and concentrated 

 upon the retina, in points corresponding in relative position to those from which 

 they proceeded, thus forming a distinct image upon the inner posterior surface 

 of the eye. In the eyes of most persons, no such image can be formed when the 

 object is brought nearer to the organ than the distance of five inches, inasmuch 

 as the rays proceeding from the object then diverge so much that the eye is un- 

 able to concentrate them to their appropriate points upon the retina, and the . 

 object then becomes indistinct and the outline confused. If, however, a trans- 

 parent medium of a proper form is interposed between the eye and the object, 

 when the latter is nearer the organ than the distance of five inches, the direction 

 of the rays of light may be so changed that the perfect action of the eye is again 

 restored, and the object clearly discerned. Such a medium is a convex lens, 



