It may be anxiously enquired why these plants 
should be so rurnished with obnoxious poison, and 
instruments to employ it; we know the immediate 
effects, but understand little or nothing of the se- 
condary causes. Such stinging plants, however, as 
are known in this country are literally harmless in 
comparison with some that exist in tropical climates. 
The poison of a species of Nettle, the Urtica cre- 
nulata, in the Botanic Garden at Calcutta, is de- 
scribed by Leschenault, in the Memoires du Mu- 
seum d’Histoire Naturelle, published in Paris, as 
most virulent. A slight touch of the plant on the 
hand, produced at first but little uneasiness ; in an 
hour it became intolerable, notwithstanding neither 
sw^elling, postule, nor inflammation took place; the 
pain extended up the arm, and threatened locked- 
jaw, continuing its violence for twenty-four hours, 
and on the second day was renewed by the hand 
being put into water. Nine days elapsed before it 
wholly ceased. Another Nettle, found in Timor, 
an island of the East Indian Sea, is mentioned as 
producing effects which continue a whole year, and 
even sometimes prove fatal. 
As far as the mechanism of the prickle or sting 
of these plants is concerned, it is clearly under- 
stood ; the specific action of their poison, however, 
has been a subject rather of conjecture than cer- 
tainty. The difficulties attending such an enquiiy 
will be obvious when it is considered that some sub- 
stances which act as a virulent poison on one spe- 
cies of animal, are nutritious to another; also, that 
others to the stomach are inoffensive, whilst through 
a wound they are fatal. 
Don’s Syst. Dot. 3, 62. 
