S Marvels of Pond-Life. 



at any angle by means of the mirror beneath the 

 stage. 



An ordinary lamp may be made to answer for micro- 

 scopic use, but one of the small paraffine lamps now 

 sold everywhere for eighteen-pence is singularly conve- 

 nient. It is high enough for many purposes, and can 

 easily be raised by one or more blocks. A paraffine 

 lamp on a sliding stand is still more handy, and all the 

 better for a hole with a glass stopper, through which 

 the fluid can be poured. 



Many people fancy that the eyes are injured by 

 continual use of the microscope, but this is far from 

 being the case if reasonable precautions are taken. 

 The instrument should be inclined at a proper angle, 

 all excess of light avoided, and the object brought into 

 focus before it is steadily looked at. Most people 

 solemnly shut one eye before commencing a micro- 

 scopic examination ; this is a practical and physiological 

 mistake. Nature meant both eyes to be open, and 

 usually resents a prolonged violation of her intentions 

 in this matter. It requires but a little practice to keep 

 both eyes open, and only pay attention to what is seen 

 by that devoted to the microscope. The acquisition of 

 this habit is facilitated, and other advantages gained, 

 by a screen to keep out extraneous light. For this 

 purpose take a piece of thin cardboard about nine 

 inches square, and cut a round hole in it, just big 

 enough to admit the tube of the microscope, about two 

 inches from the bottom, and equidistant from the two 

 sides. Next cut off the two upper corners of the card- 

 board, and give them a pleasant-looking curve. Then 



