On Preserving, Organte Pu 339 
My plan consists in wholly abstracting the moisture from the 
specimen to be preserved, having previously inclosed it in some 
material impervious to air or moisture, in order that the condition 
of absolute dryness may be perpetually maintained, The desic- 
cative substance which I make use of, is unslacked lime ; and. 
though other agents might be used, this seems to answer in all 
Cases so perfectly, well, as to leave nothing to be. desired, Pure 
quick lime, it is well known, will absorb near one third its weight 
of water in the process of slacking, Telsing a powder Per 
as free from moisture as at first. 
_ IL will first explain the manner in which botanical specimens are 
to be framed for constant ‘exposure on the walls of a museum or 
lecture room. 
Take a specimen, recently dried in the usual way, between 
folds of bibulous paper, in order that every shade of color may be. 
natural and fresh as. life ; procure - -a pane of glass of sufficient 
size, and a plate of tin, zine, copper, or sheet lead,* half an inch 
longer and half an inch broader than the pane of glass; bend 
_ this around the edges so that it will embrace the glass; remove 
the latter, and place in.the shallow cavity a thin layer of cotton 
batting ; upon this, sift a thin stratum of the powder of quick 
lime ; over this another: layer of batting; upon this a sheet of 
‘issue paper, and on the tissue paper, the specimen and label. 
Over all, place the clean pane of glass; press it gently down, 
and carefully turn over it the edges of the metallic plates. Se- 
cure the junction of the glass and metal with a ceroid or resi- 
hous cement, as bees’ wax, shellac, or sealing wax: or what is 
more convenient, and seems to answer well, fill the crevices with 
stiff glazier’s putty, and when that gets ary, pass over it with 
thick Japan varnish, of which two or three successive coats may 
be used. If the back be of sheet tin, zine, copper, or thick sheet 
lead, a ring may be soldered to one end, for the purpose of hang- 
ing up without further preparation. But if very thin sheet lead 
be used, it may require to be first protected by a back of binder’s 
board and some kind of frame. 
‘With a view of subjecting theory to the test of experiment, I 
enclosed in this manner a dried specimen of Lycopodium apodum, 
‘and also attached a part of the same specimen by means of stick- 
een 
The sheet lead which lines tea boxes answers very well. 
