Xll INTRODUCTION. 



farm it will enable the agriculturist to examine closely and minutely 

 the various noxious insects and forms of fungi and blight, and thus 

 aid him in identifying them and applying the proper remedy; and 

 in the examination of minute seeds, such as timothy, clover, etc., it 

 will prove a very valuable assistant, enabling him to detect any in- 

 feriority in the quality, or any impurity or adulteration. Frequently 

 the agricultural seeds offered in market contain minute seeds of of- 

 fensive weeds, many of which are so small that they are not easily dis- 

 covered by the naked eye. 



Every farmer and mechanic knows the value of a good pair of 

 eyes, and he also knows that an agent which doubles or trebles our 

 power in any given direction at once confers upon us in that respect 

 a superiority over our fellows. Very few men are twice as strong as 

 their comrades; still fewer have three times the strength of ordinary 

 men, and it may be safely affirmed that no man possesses the power 

 of ten ordinary men. But a microscope of very ordinary capacity at 

 once multiplies our powers of sight by ten, twenty, or even a hun- 

 dred times, while those of the better class enable us to see things 

 with a keenness and clearness which, when compared with that af- 

 forded by the naked eye, is as more than a thousand to one. 



There are four distinct and important directions in which a mi- 

 croscope may be made to serve us: 1. It is capable of affording the 

 most refined and elevating kind of pleasure by the exhibition of ob- 

 jects of extreme beauty and interest. There are few more splendid 

 sights than the gorgeous colors displayed by.some objects when 

 viewed by polarized light, and even the tints of certain minerals, 

 and the brilliant scales of certain insects, when viewed as opaque 

 objects, by means of a good condenser, surpass anything that is 

 familiar to us in our ordinary experience. On the other hand the 

 exquisite beauty of form which is characteristic of most of the ob- 

 jects with which the rnicroscopist concerns himself can be fully ap- 

 preciated only by those who have seen them. As a source of inno- 

 cent amusement and pleasure, therefore, the microscope has few or 

 no equals; for it may be safely affirmed that a five-dollar instrument 

 is capable of affording gratification of greater variety and intensity, 

 and of longer continuance, than that yielded by anything else of 

 the same cost. This arises chiefly from the fact that most other in- 

 struments, when once exhibited, with their slides or fixtures, lose 

 their freshness and interest, and become old. While for the micro- 

 scope, a few fibres of wool from the carpet, a few grains of sand from 

 the sea-shore, or a handful of wild flowers from the field, yield ob- 

 jects of surpassing beauty. Everything in nature and in art may bo 



