INTBODITCTION. 



I. USE OF THE MICROSCOPE AND EXAMINATION OF 

 MICROSCOPIC OBJECTS. 



BEFORE entering upon the special consideration of the Microscope, of which the Intro- 

 duction treats, it may be well to make a few remarks upon the general use of the instru- 

 ment in the examination of minute objects. 



The Microscope will either be used as a means of affording amusement, or with a view 

 to scientific research. In the former light, no philosophical instrument can compete with 

 it, in regard to the great variety, the beauty, and the wonderful phenomena of structure 

 which the minute objects it enables us to examine display, even independently of the con- 

 sideration of the functions and uses of their several parts. In this light also, the inves- 

 tigation of the comparative structures and properties of various bodies or substances 

 used in daily life as articles of food, dress, &c. will form subjects of intense interest to 

 any one who may be possessed of the instrument. The mysterious phenomena of growth, 

 reproduction, and crystallization may also be watched throughout their progress, j ust as 

 we can see the effects of parts of machinery with the naked eye. But while the sense of 

 sight is thus gratified, the mind will not be unoccupied ; for every fresh appearance will 

 impress a new fact ; so that here we have both amusement and instruction combined. 



It is, however, to the use of the Microscope as a means of scientific research that our 

 remarks are most necessary ; for in this great care and consideration are required, and 

 these are very apt to be neglected by those who are unaccustomed to employ this valuable 

 instrument. 



The Microscope as a means of investigation might perhaps be thus defined : the micro- 

 scope is an optical instrument constructed in order to enable us to investigate the characters 

 and properties of those objects which we are unable to study with the unassisted eye, on 

 account of their minute size. 



The use of the Microscope will resolve itself into either that of proving the structure of 

 a known object, or determining that of a new one ; and in thus applying it, exactly the 

 same precautions must be adopted, and just the same course pursued, as if the object under 



