246 BENJ. PIKE'S, JR., DESCRIPTIVE CATALOGUE. 



convex lens, to condense the light upon the object ; D the 

 slider of objects ; E, two plano-convex lenses, forming an 

 achromatic eye-piece, through which the rays of light pass, 

 and depict the object of an immense size upon a screen pre- 

 pared to receive it, in the same manner as in the exhibition 

 of the magic lantern. Price, $80.00 to $150.00. 



Fig. 7GO. 



Microscope Sliders. (Fig. 760.) These consist of a flat 

 strip of ivory, having four round holes wherein to place 

 small objects between two pieces of talc, or isinglass, which 

 are confined by a small spring ring. Several such sliders 

 usually accompany microscopes of good quality. 



Price, a set of 6 sliders, $3.00. 



Directions for procuring and applying the most interesting 

 Subjects for Examination by the Microscope ; also the 

 method of procuring those wonderful Objects of the 

 minute creation, the Animalcula in Vegetable In- 

 fusions. 



MANY persons who have purchased microscopes, after 

 entertaining themselves and friends with the slides that ac- 

 company the instrument, have found themselves at a loss for 

 new objects, and consequently, have laid it aside as of little 

 further use. No invention is capable of affording more en- 

 tertainment and instruction than the microscope ; it opens a 

 new world, and displays the most extensive scenes of crea- 

 tive power, wisdom, and design. 



Objects for the Microscope. In the summer months, the 

 waters, as well as the fields, abound with living wonders for 

 the microscope, and afford an endless amusement to the 

 admirers of the works of nature in the minute creation. 



Best method of procuring Aquatic Insects. In the ponds 

 and ditches that are covered with duck-weed, surprising in- 



