62 THE Microscope. 
WHITE ZINC CEMENT. 
Cc. H. STOWELL. 
‘“ White zine cement has been much used, and is, unfortunately, 
still employed to some extent. It is a very pleasing cement to work 
with, but all we can say of it is that if the preparer wishes to be 
assured that a certain proportion of his mounts will be spoiled sooner 
or later by the running in of the cement, let him use the white zine.”’ 
—R. Hiteheock, in February No. of American Monthly Microscopical 
Journal. 
] HITE zine cement is not only the most pleasing cement to 
work with, but is also as durable as any cement in the 
market. Nothing can take its place for a glycerine mount. A 
recent writer has said that “ only the careless and slovenly have 
trouble with their cells breaking when white zine is used as the 
cement.’ Neither will it run in and spoil the mount if it is 
properly put on. 
I have a few slides that show where the cement has run in, 
but these are caused directly by my own haste or carelessness. 
If our readers know of any cement better for glycerine 
mounts I should like to have them make it known. 
I use it altogether in laboratory work for balsam mounts 
also. Here more care is needed to make a neat looking finish, 
but in the end we have a durable and also attractive mount. 
After mounting in balsam, a thin layer of colorless marine glue 
is placed around the edge of the cover, just coating the exposed 
balsam. This dries very quickly; when dry, a thin layer of the 
white zine is put on and the mount is then laid aside for a few 
days. The second coat of zinc will finish the slide in good 
shape, and none of it will run in either. 
The colorless marine glue is dissolved in fusel oil, and is 
unaffected by benzole, hence it serves as a perfect wall between 
the benzole of the zinc and the soluble balsam within. 
Of course some of our students have occasional trouble 
with the running of the zinc, but then—poor students, haste, 
inattentiveness to details; these always must result in poor 
mounts. Brunswick black, gold size, Brown’s rubber cement, 
Bell’s cement, they are all good; but white zine is the cement 
tor every day use. 
