247 
Of the Bark of Roots. 
quor, caufes them to be of a milky i! , or other opake co¬ 
lour. In the fame manner as common oil, and a flrong 
liquament of tartar, {hook in a bottle, become white. 
Sometimes the oil will feparate, as is obfervable on 
cutting a fennel root tranfverfljr, after it hath lain fome 
days out of the ground. The fame vefiels, which before 
yielded milk, will now yield oil. 
All gums and balfams are likewife the contents of thefe 
vefiels, for thefe and milks are nearly a-kin. The milk 
of fennel {landing fome time, turns to a clear balfam, of 
fcorzonera; dandelion, and others, to a gum. In the 
dried root of angelica, when fplit, the milk 1 is feen in 
clods, in the continuation of thefe veffels, ccndenfed into 
an hard {hining rofin. The root helenium cut tranf- 
verfiy, prefently yields a balfam of a citron colour, fo 
called becaufe it will not dhTolve in water. The root of 
common wormwood yields a true balfam, with all the de¬ 
fining properties of a terebinth ; the roots of trachelium 
and enula, yield both a lympha and a citron balfam; and 
wormwood both a lympha and a terebinth k at the fame 
time. It is doubtful whether all roots have lymphaedu&s, 
but probably they have, and for the moil part {landing in 
a ring, at the inner verge of the bark. 
Thefituation of thefe vefiels are very curious, if viewed 
in a tranfverfe ledtion of the root; fometimes they only 
form a ring at the inner edge of the bark, as at E F, in 
afparagus, fig. 467, in which pcfition they are in mofl, 
if not all roots ; in fome they {land in rays, as borage, or 
peripherial, as in celandine. Thefe vafcular rays are ex¬ 
tended in fome towards the circumference of the bark, 
about half way, as between C D E F, in buglofs, fig. 
475. in all docks and forrels, about three fourths of the 
thicknefs of the bark towards the circumference, feveral 
R 4 of 
h Grew. An. Plant, p. 67. 1 Ibid p. 67. k Ibid. p. 68. 
