/ 
^.15 
\ 
an odd one, wliich is the largeft : the flowers are 
difp 
f. 
d 
m 
fli 
fpikes, and appear in June and July: the corolla confifts of 
four petals, which 
of a whi 
emities are roundiih, fpreading 
d 
fall 
alyx is of four oval leafits, which commonly 
oif by the expanfion of the flower : the ftamina are fix, four 
g and two fhort, and furniihed with fimpl 
; the ftyle is 
fhort, with an obtufe ftigma : the germen is long, flender, and becomes 
fmall round feeds. It is a native of 
\ 
ed pod, which 
waters 
Britain, and grows commonly in brooks and fla 
" The leaves of the Water-creffes have a moderately pungent tafte, 
emit a quick penetrating fmell, like that of muftard-feed, but much 
weaker. Their pungent matter is taken up both by watery and fpi- 
lice, vv^iich iffues 
/ 
rituous menilrua, and accompanies the aqueous j 
j^ 
copioufly upon expreffi 
very volatile fo as to arife 
part 
diftillation, vnth rectified fp 
g 
well 
with water 
A 
d 
almoft totally to exhale in drying the leaves, or infpiflating by the 
gentleil heat to the confidence of an 
ad:, either the 
expreifed 
or the watery or fp 
tindures. Both the mfpiifated 
juice, 
juice, and the watery extrad:, difcover to the tafte a faline impregna- 
tion, and in keeping throw up cryftalline efflorefcences to the furface. 
On diftilling confiderable quantities of the herb with water, a finall 
proportion of a fubtile volatile very pungent oil is obtained " ^ 
Water-creiTes obtain a pi 
the Materia Medica for their 
\ 
fcorbu 
qu 
which have been long very generally acknow 
ledged by phyfi 
They 
alfo fuppofed to purify the blood 
and humours, and to open vifceral obftrudions 
> 
ey are 
ly 
■\ 
allied to fcurvy-grafs, but 
mild and pleafant, and for this 
reafon are frequently eaten as fallad. In the pharmacopoeias the 
juice of this 
is dired:ed with that of fcurvy-grafs and S 
oran 
g 
and Dr. Cullen has remarked, th 
the 
ddit 
of acids 
( 
renders the juices of the plantse filiquof^ more certainly efFedual, by 
determining them more powerfully to an acefcent fermentation.'* 
/ 
qual 
r 
This volatile matter has been erroneoufly 
* Lewis Mat. Med. 
Hoffman and Haller thought highly of its powers in th 
No, 10, 
Mat. Med 
M m 
N 
POLYPODIUM 
\ 
