17 
summer months of higher latitudes ; consisting of wheat, 
barley, flax, peas, beans, &c. with the culture of the 
poppy, and the collection of opium, in the very same 
fields, perhaps, where, in the rainy season, had been grown 
rice, sorghum, and other tropical grains. 
Such are a few general views respecting the Geography of 
plants in connexion with climate. Between the extreme 
points of a tropical and a polar vegetation, we might shew 
a series of gradations : but these would lead into unneces- 
sary detail ; and the object has, perhaps, been sufficiently 
gained, if I have been successful in shewing in what way 
the distribution of plants is connected with climate ; and 
consequently what is the value of any inferences that may 
be deduced from their culture in new situations ; and also 
from vegetable products being found in countries where 
the plants themselves are unable to grow. 
The Animal creation is the next which should attract our 
attention, or at least be considered in connexion with the 
vegetable kingdom, whether we adopt the ascending or the 
descending series. Here we find sensibility superadded to 
the vital principle, which we first saw in union with 
matter in the lowest forms of organized vegetation. Inte- 
resting and instructive as is the study of the forms and 
habits of the animal world ; indispensable as is an acquain- 
tance with their internal structure and functions to a scientific 
knowledge of the anatomy and physiology of the human 
frame ; these are of comparatively less consequence in a 
course of Materia Medica : because in proportion as the 
progress of medicine has brought the art of prescription 
nearer to its original simplicity, so the crowd of inert and 
disgusting remedies, introduced by the corrupters of medi- 
cine, have disappeared from our pharmacopoeias. As animals 
require for their nutriment matter which has already been 
organized, either by vegetables or lower grades of animal life, 
D 
