[ 92 3 
Myrrhis fylveftris leminibus afperis. This, like the 
cow- weed before-mentioned, can only be miftaken 
for hemlock in the fpring. It may be diftinguifhed 
then from it, by the leaves of the myrrhis being 
more finely cut, of a paler green colour, and, though 
they have fomewhat of the hemlock fmell, are far 
lefs firong, and have no fpots. This plant flowers 
in April, and the feeds are ripe before the hemlock 
begins to flower ; and thefe feeds are cylindrical, 
rough, and terminate in an oblong point. 
The leaves of hemlock are moft fit for medicinal 
purpofes, as being in their greatefl: perfection, when 
collected in dry weather, from the middle of May 
to the time that their flowering Items begin to fhoot; 
as by that time the plants will have felt the effects 
of the warm fun, have acquired an highly virofe 
fmell, and the Items of the leaves are covered with 
purple fpots, an argument of the exaltation of their 
juices: and we fhould be attentive here to give them 
all thefe advantages, as three degrees of latitude, and 
other circumftances of foil and fituation, may oc- 
cafion a very fenlible difference in the qualities of 
the fame plant ; an inftance of which occurs in the 
plant under confideration, and may be one of the 
caufes, why the effects of the hemlock have not 
been fuch here, as we are affured they are at Vienna ; 
viz. Dr. Storke fays, that the root of hemlock, when 
cut into flices, pours forth a milky juice, which I 
have never feen it to do here in England. 
There are feveral vegetables, which, though they 
thrive apparently well, their productions are, never- . 
thelefs, not the fame as in other parts of the world, 
where the heat is more intenfe, and the fummers are 
of - 
