MATERIA MEDICA—BOTA ¥. 
. eave, some of them aequiring activity from age, 5; Walk ‘ 
ginous leaves, from the same cause losing the pro 
y are officinal. Aromatics are to be collected aft ; 
: re formed ; annuals, not aromatic, when they are about — 
el or when i in flower ; biennials, before th 
cogent distr = 
‘Barks and woods are Feallewick when HE st active eee of the 
vegetables are concentrated in them, which happens in the spring 
and Autumn. Spring is preferred for resinous barks ; and Autumn 
for others, which are not resinous but rather gummy. Barks should 
be taken from young trees, and freed from decayed parts and all 
impurities. 
The same rules direct the collection of woods ; 3, but 
taken from very young trees. Among the resin 
heaviest, which sink in water, are selected. — 
be rejected. j 
* Flowers are collected i in clear, dry weather, bei 
the dew is off; either when they are about to ope 
after they have opened. Of some, the pets sy ‘or colored flower. 
leaves, only are preserved, and the colorless claws rejecte ae 
others whose calyx, or outer covering, is odorous, the whole :  . Sa 
_iskept. Flowers which are too small to be plucked singly, aredried 
vith part of the stalk. “These are called heads, or tops. 65 
Flowers are to be dried nearly as leaves, but more quickly, and 
th more attention. As they must not be exposed to the uy itis 
est done by a slight degree of artificial warmth. - : 
E Seeds and ripe fruits, unless when otherwise directed, are to 
: red when ripe, but before they fall spontaneously. 5 
ky fruits are freed from their core and seeds, strung upon threads, — 
and dried ne ete They are in general best preserved in thei 
Natural coverings, although some, as the colocynth, are = 
and others, as ti ¢ tamarind, preserved fresh. Many of these. at = 
: ge: become rancid ; and as they are then not fit for medi-~ 
tal use, no very large ven of them should be collected ata 
RP sa 
The proper drying of vegetable substances i is of the greatest im- 
= ee ch. Prt is pes dunected to be done in the shade, and slowly, 
- that the volatile and active particles may not be dissipated by too 
great a heat; but this is an error, for they always lose more a 2 
Slow, than by a quick drying. When, on account of the color; they 
fannot be exposed to the sun, and the warmth of the stop acrs 
eeenciont, they should be dried by an artificial heat, nots 
ee Ss breahost and well exposed to a current of air. Wh 
, they ae little al at : 
