304 Of Charcoal, or burnt Vegetables. 
corner; then take your flowers, leaves, &c. when full 
ripe, and of their true colour, fpread them on a browiS 
paper, with the leaves as diftindt as you can ; if the 
flowers are large, more paper muft be laid under them ; 
and if thick you may pare away half thereof, as alfo of 
the Araik fo as to lie flat; then put thefe between the iron 
plates, fcrew them faflr, and fet them in an oven for two 
hours; after which take out the flowers, and with a 
brufh dipped in equal quantities of aqua fortis, and aqua 
vitae, or brandy, pafs over the leaves and flowers; then 
jay them to dry on frefti brown paper, and take the 
quantity of a walnut of gum dragon, which in lefs than 
twenty-four hours v/ill be diffolved in a pint of water, 
and with a brufh rub the back-fides of the leaves and 
flowers to make them flick; then lay them into your 
paper-book, and they will always look frefh g . 
Of charcoal, or burnt vegetables. 
C Harcoal, or a vegetable burnt black, affords an ob¬ 
ject no lefs pleafant than inflrrudtive; for if a final! 
piece of charcoal be fuddenly broke, it will appear to have 
a very fmooth furface, but if examined by the microfcope, 
abundance of pores are difcoverable in many kinds of 
Wood, ranged round the pith both in a circular and a 
radiant order; and moft of thefe fo exceeding fmall, and 
fo clofe to each other, that but a very little fpace is left 
between them to be filled with a folid body. Thefe 
pores, or rather tubes, are fo extreamly fmall, that in a 
jjne of them, one eighteenth part of an inch long, Mr. 
Hook reckoned no lefs than an hundred and fifty, therefore 
in a line an inch long were no lefs tfyan 2700 pores, 
and 
s Phil. Tranf. No, 22-. 
