OUTLINES OF BOTANY. LX XIII 
put into hot paper will require changing very soon, to prevent their 
turning black, for = roe without ventilation produces fermentation, 
se spoils the specim 
. For pressing plants, various more or less complicated om costly 
tiers are made. None is better than a pair of boards the size of the 
paper, and a stone or other heavy weight upon them if at home, or 
pair of strong leather straps r round them if trav elling. E ach of thes 
ese 
boards should be double, that is, made of two layers of thin boards, the 
opposite way of the grain, and joined together aiohy he yh clenched 
brads round the edge, without glue. § rds * les 
than half an inch thick (each layer about 21/ lines) will te foot light 
and durable. 
238. It is useful also to have extra boards or gat otgane the size a 
the paper, a eaten thick plants from thin on 8s from thos 
arash dry, etc. Open wooden frames with cross- sate or pith of oak 
wir k lattice, are still better than esha for this purpose, as 
sooelerating rene oe ing by promoting ventilat 
. The e frequently the vee are shifted into dry paper the 
‘ee er. Mesiea g for tiff or woody plants, the first pressure should 
be light, and the first shifting, if poss ible, after a few hours, Then, or 
at the eneed shifting, w pecimens Ng have lost their clasticity, 
will be the time for patting ne any par a specime ay 
have taken a ae fold o Ries direction. Anes this the tgisnatice may 
in e e 7 
sever 
without shifting. "The exact amount of pressure to be given will depend 
on the consistence of the alk bers a and the amount of paper. It must 
only be borne in mind that too much pressure ae the delicate parts, 
too little allows ae to shrivel, in both cases interfering with their 
— examinatio 
st ueiient specimens will be made, if the drying-paper 
is the e same size as that of the herbarium in which they are to be kept. 
That ri vaio demy, rather op than 16 inches by 10%/2 inches, is a 
comm Vv convenient s A small size reduces pe ase imens 
too eats a large size is both euty and inconyenient for 
241, When the specimens are quite dry and stiff, they ra ‘be packe d 
is 
. 
he 
re 
must be taken to protect the bundles by sufficient covering from the 
of € al moi ec 
242. In laying the specimens into the herbarium, no more than on 
rear ret _—— ever be fastened on one sheet of paper, alt toh ra 
of the same species may be laid side by side. And throughout 
e pistons of drying, packing, and laying in, great care must be taken 
re saps fe 
Notion 01 softer ie then If the parts are very delicate, this is best done 
ing t 
by gra nae moistening them in cold water; in most cases, steep 
in boiling ‘steam is much ada beset Very hard fruits and eeds 
e 
sary is a Seharsatre and a pocket lens of two or three glasses from 1 to 
2 inches focus. At home it is more convenient to have a mounted lens 
