BOTANICAL GAZETTE. 413 
Glass plates. A number of these should be provided large 
enough for the bell-jars or tumblers. By this means air-tight 
¢ells can be made by oiling the bottom of the bell-jars. 
up plates are very useful for keeping many specimens in, 
especially the aquatics in such common use. The glass plates or 
bell-jars can be used for covering them. 
Watch glasses, The ordinary watch glasses are in common 
use for holding small specimens, and especially for containing 
the reagents used in treating sections. The ease with which they 
are overturned is spoken of, and a remedy suggested in securing 
those with flat bottoms. A still simpler and safer way is to use 
individual salt-cellars. 
manent mounts, and thus preserves everything wat promey es 
but never mounts for mounting’s sake. It is questionable whether 
_ lm the time devoted to the study in most of our la guia 
Much attention should be paid to this purely ee ‘k 
the work. In reference to permanent mounts swig ara od 
makes the following suggestion: “ When an object is mount 
and designed for preservation, an occasional difficulty 1s expe 
_ Tieneed as to some suitable substance which is fairly ap ld 
_ Which will not ran under the cover when used as a ring . 0 : 
cover in place. For this probably nothing 18 sagan an : 
Tather thick solution of gum shellac in alcohol. This will mee’ 
the shellac hardens, as it will quickly, a final ring may 
~ en be run over it. This is especially valuable w 
8 mounted in any of the balsam preparations 
Ps Ab s t 
; ceived 4 pos above given enibeuy id while professional workers 
oth cheap and efficient, w! 
o what they need, by those who have had much ex- 
 Petience in such matters. 
