of Warming and Ventilafing Buildings. 47 
densing the vapour when many people assemble in a room that 
has not for some time been used. 
(To he concluded in next Number.,) 
Art. V. — On certain Antediluvian Plants susceptible of being 
illustrated by means of species now living within the Tropics. 
By Dr C. F. P. De Martius. Read at a Meeting of the 
Royal Botanical Society of Ratisbon. 
To acquire a distinct conception of the various changes which 
our terraqueous globe has undergone ; to discover the manner 
in which the different strata have been superimposed upon the 
internal nucleus of the earth, as well as their relative position ; 
to contemplate the first origin of living beings, and determine 
the point from whence they have proceeded to overspread the 
whole surface of our planet, are justly considered as among the 
most elevated pursuits, and the most becoming in which men 
can engage. For thus deriving knowledge from those primeval 
and silent monuments, we transform ourselves into spectators 
of ages unseen by mortal eyes, and discover the first principles 
on which to found our reasonings with regard to the origin, 
evolution, and increase of our race. 
There is but little, indeed, regarding the first history of our 
planet, and that little very doubtful, that we can avail ourselves 
of, in contemplating the various conditions of inorganic bodies 
in former times, and hence we form a very difficult and uncer- 
tain judgment concerning the primitive mass of the earth and 
its chaotic changes. For, so far is it from being the case, that 
the light which has been thrown upon geology by the wonder- 
ful discoveries daily made in chemistry and natural philosophy, 
has dispelled the whole of the darkness in which it has been in- 
volved, with respect to the evolutions of the primordial ele- 
ments, that, rather while it illustrates some things, it is per- 
* A copy of this Memoir was obligingly couimunicated for this Journal by the 
author.— -E dit. 
