THE MICROSCOPE AND ITS PARTS. 5 



and sold as a remarkable thing. The lens was a small 

 globule of glass fastened to a glass plate, to give it a 

 flat under-surface, and mounted in a brass ring, the 

 whole being supported on an upright brass tube with a 

 plane mirror at the lower end. It was not a com- 

 pound microscope, but a simple lens with mirror at- 

 tachment. The object to be examined was suspended 

 from the fiat surface of the glass in a drop of water, 

 the focus being so short that it was at the front of the 

 lens, so that nothing could be looked at unless it was 

 actually adherent to the glass. No mounted object 

 could be satisfactorily studied; to examine the parts of 

 a flower was impossible, and even when a drop of 

 water was suspended from the lens its trembling was 

 exasperating, and its contents were distorted almost 

 beyond recognition. All similar instruments should 

 be avoided. 



The "Excelsior Microscope" makes no false pre- 

 tences. It consists of a small box, which acts as a re- 

 ceptacle for all the parts when not in use, and as a 

 support when a steel rod is elevated to receive the 

 combination pocket-lens and the stage on which the 

 object is to be placed, a small mirror in the front of 

 the box reflecting light to the object from below. A 

 great fault is the absence of weight in the instrument. 

 At the least touch it moves, the light reflected from 

 the mirror is lost, and the object is consequently left 

 in semi-obscurity. It is, intended chiefly for the dis- 

 section of flowers, grasses or large insects, and fairly 

 answers the purpose if the observer desires to have 

 both hands free, and cares to screw the box to the 

 table. But it is no better than a good pocket-lens, 

 which, with very little trouble, can be attached to an 



