258 Of Leaves. 
Prickles, that penetrate the Skin when 
touched, and occafion Pain, Heat, and Swel¬ 
ling : which Symptoms were imagined for¬ 
merly to enfue from the Prickles being left 
in the Wounds they make. But the Micro - 
/cope difcovers fornething much more won¬ 
derful in this common Vegetable, and fhews 
that its Prickles are formed and ad in the 
fame Manner as the'Stings of living Animals. 
For every one of them is found to he a rigid 
hollow Body, terminating in the moil acute 
Point imaginable, with an Opening near its 
End. * At the Bottom of this Cavity lies 
a minute VefTe! or Bag, containing a limpid 
Liquor, which, upon the lead: touching of 
the Prickle, is fquirted thro’ the little Out¬ 
let ; and, if it enters the Skin, produces the 
Mifchiefs before-mentioned by the Pungen¬ 
cy of its Salts. Hence it comes £0 pafs, that 
when the Leaves of Nettles are confiderably 
dried by the Heat of the Sun, they fling but 
very little : whereas fuch as are green and, 
juicy produce violent Pain and Inflamma¬ 
tion. But the quite contrary to this would 
happen, if the Symptoms were only owing 
to the Breaking of the Prickles in the 
Flefh : iince when dry they mu ft be more 
brittle, as well as more rigid, than wdien 
they abound with juice. 
# Hook’s Micrgg. pag. 142. 
p. 10/. 
Arc. Nat. Tom. I. Par. Ill, 
Suere-% 
