22 
The VEGETABLE SYSTE M. 
nor is it limited to thefe : there is much more to be yet nfferted con- 
cerning thefe ; but let the truth which is a Granger, difplay itfelf by 
juft degrees. 
It fhould Teem in the firft place, that there are a certain num- 
ber of univerfal Plants, which grow in every kingdom ; and are Ve- 
getables of the Globe, not of this or that quarter of it. 
We fhall find moft of thefe to be the Plants, whofe fituation ren- 
ders the power of Elements almoft equal in whatever part they grow. 
The greater number of them are inhabitants of high mountains and deep 
waters; here the temper of the air is- lefs altered by the climate, and 
we therefore may lefs wonder at feeing the fame Plants : but all that 
are common to fo remote regions, and fo different climates, are not the 
natives of thefe peculiar places. The Xanthium, our prefent fubjedt, 
grows upon the rubbilh about Canton, as freely as at Nottingham 3 nor 
is this a Angle inftance. 
There is a certain tracft about the North Pole, wherein, for the 
whole circuit, the fame Plants are found; perhaps it is the fame about 
the South Pole, but the country is unknown. As it is hard to fay how 
far North America extends, cr what are the limits where it joins, if 
it does join, with other northern countries ; we are accuftomcil to call 
the extream northern world, by a name deduced from its place, and 
to give one term to the extent of kingdoms this way, to whatever 
others they belong; calling them the Polar Countries. If we exa- 
mine the Vegetable products of thefe countries, we fhall find them 
nearly the fame in all ; and in a certain latitude, that difference be- 
tween American and European Plants, which has been fancied fo abfo- 
lute, ceafes entirely. 
The Plants of the extream North, fo far as we know, are all the 
fame ; all low ; and all of what are ulually called the imperfedt Kinds : 
From this northern tradt, where the circuit of the Globe is confined in 
very narrow limits, they fcem to have extended every way, and to have 
encreafed in parts, and ftature. 
3 
There 
