THE MICROSCOPE. 29 
mounted needle place a drop of clean water on the 
centre of the slide. From the frayed edge of a hole 
in your handkerchief, cut with scissors a very small 
fragment of linen thread, and place it in the drop of 
water. Place the slide on a piece of dead black 
paper, and with a pair of mounted needles tease out 
the linen thread as much as possible. Cover it 
gently with the cover-glass. Take up the surplus 
water round the margin of the cover-glass with a 
slip of blotting paper. Take up so much of the 
water that the slide can be held perpendicularly with- 
out the cover-glass slipping off If, however, the 
first drop of water was not sufficient to fill the whole 
of the space between the cover-glass and the slide, 
take up another drop with the handle of the needle, 
put it on the slide close to the cover, and let it run 
in under the cover. If there now [should be too 
much, remove the surplus with blotting paper. 
b. Incline the body of the microscope to a convenient 
angle. Screw on the inch objective. Put in the 
shallowest eye-piece, and close the draw-tube. Centre 
the mirror with the axis of the body, and arrange it 
so that a good light passes up the instrument. The 
easiest way of doing this is to look at the lower 
surface of the stage, and move the mirror until the 
light is thrown through the central opening; then 
looking through the eye-piece, a very little more ad- 
justment will give the best illumination. Turn on 
the largest aperture of the diaphragm-plate. | 
c. Draw back the body. Place your prepared slide on the 
stage, and gradually focus down until you see the 
object. Move the slide about on the stage while you 
are examining the linen fibres. This requires some 
