184 THE MICROSCOPE. 
all is dissolved, strain through linen and set aside for about a week 
to get rid of air bubbles, and allow any particles which may have 
filtered through to settle; or filter through absorbent cotton by using 
a funnel for hot filtration, which consists of a double tin case 
holding water, kept at the required temperature by a spirit lamp 
placed under the projecting area. A glass funnel fits inside 
the hot-water bath, a plug of absorbent cotton is placed in the 
funnel, and the solution is passed through it. After filtration, it is 
best preserved in compressible tubes. 
To mount starches or pollens, a clean slide is breathed on and 
then dusted over with the starch or pollen to be mounted. The 
surplus is removed by gently tapping the slide against any hard 
substance—a table, for instance. Enough of the starch will adhere 
to the slide, and will be nicely distributed over the field. A drop of 
the mounting medium is now carefully placed on the slide, and the 
cover placed over it. If there are any air-bubbles in the mounting 
medium when placed on the slide, they should be carefully picked 
out with a mounting needle. If the medium is kept in a compres- 
ible tube, there is not much danger of air bubbles on squeezing out 
a drop; or if there are any, they will be on the surface, and can be 
be readily removed with a mounting needle. The slide can then be 
finished immediately by running a ring of any kind of cement 
around the edges of the cover-glass, and the mount is permanent. 
The medium can be colored blue by adding a small quantity of 
anilin blue, although it is not necessary, as the structure of the 
starches can be plainly seen. They should be examined by centra 
and oblique illumination, and with the polariscope, to give the 
student interested in this subject an idea of the beauty of starches 
and pollens. 
Mountine Fiso Scates.*—Mr. Frederick DuBvis gives the 
following directions for preparing and mounting the scales of fish: 
Place the scales in a small, wide-neck bottle of caustic potash for 
forty-eight hours, then boil for a few minutes in plain water, and 
afterwards wash in hot water. Partially dry the scales between 
blotters, and place in alcohol for quarter of an hour to remove all 
moisture. The scales are then transferred to clove oil for clearing. 
Now breathe on a clean cover-glass, and apply side breathed on to a 
glass slip, to which it will adhere. Place a small drop of benzol- 
balsam on the cover, put the scale on this, cover it with another 
drop of balsam, and set aside for twenty-four hours. By the 
*The Garner, May, 1889. 
