154 PREPARATION AND MOUNTING 
the same length of time, so as to soften and render it easy 
to cut. Sections may then be obtained in the manner just 
described, but they often curl to such a degree from their 
previous immersion in water as to render pressure necessary 
to flatten ‘them until dry. They are often mounted dry, 
and require no care beyond other objects, as in Chapter 
III. Some, however, are best mounted in balsam, par- 
ticularly the long sections when used for the polariscope; 
these must be soaked in turpentine, and the greatest care 
taken that all air-bubbles are removed. Others are thought 
to be most useful when mounted in shallow cells with some of 
the preservative liquids mentioned in Chapter V.—weak 
spirit and water, chloride of calcium solution of the strength 
of one part of the salt to three parts of distilled water, &c. 
The above “ section-cutter”’ may not be within the reach © 
of every student, nor is it absolutely necessary ; though where 
any great nwmber of specimens is required it is very useful, 
and insures greater uniformity in the thickness. Many 
employ a razor for the purpose, which must always be kept 
sharp by frequent stropping. Sections of leaves also may 
be procured by the same means, though, as before mentioned, 
they are sometimes divided by stripping the coatings off 
with the fingers. The cells which come to sight by cutting 
some of the orchideous plants are most interesting. Tocut — 
these leaves they may be laid upon a flat piece of cork, thus 
exposing the razor to no danger of injury by coming in 
contact with the support. It may be mentioned here that 
the razor may also be used in cutting sections of the rush, 
than which a more beautiful object can scarcely be found 
when viewed transversely, as it shows the stellate arrange- 
ments of the parenchyma. This should be mounted dry. 
In the same way sections of the leaf-stalks of ferns may also 
be cut, some of which, as Dr. Carpenter states, show the 
curious ducts very beautifully, especially when cut rather 
obliquely. 
It has been found a ready method of cutting sections of 
the rush and such like plants, to suck a solution of gum up — 
