314 
aqueous compound. The apparent insolubility of quartz was 
at one time the argument held in favour of the igneous theory, 
although silica was found in solution. Silica is now artificially 
dissolved, and can be obtained as plastic as clay ; therefore 
there is not a single case connected with the materials of 
which the globe is composed to warrant the assumption that 
they originated from fire. On the contrary, all the observed 
facts confirm the belief that the crystals first came forth and 
grew from water, and that the lands have gradually risen from 
the deep. 
The evidence of successive elevations and depressions is so 
manifest as not to require further remarks. The evidence is 
equally strong that the various deposits of organic remains 
have not only been lifted from the deep, but have also been 
carried en masse from clime to clime at a slow rate, inasmuch as 
the deposits of the northern hemisphere, as far as the Arctic 
region, contain all the organic productions of the world. 
This subject, however, will have to be treated separately, in 
connection with the probable ages of geological formations 
founded on astronomical data. 
Superficial Changes. 
The changes going on over the face of the earth are much 
more rapid than the public at large appear to be aware 
of. The deposits in deltas are frequently formed in great 
thickness, in a comparatively short time, by mountain torrents, 
floods and avalanches. The great region between the rivers 
Orinoco and the Amazon is intersected by rivers, and covered 
here and there with shallow lagoons, subject to periodical 
floods. This country is so overloaded with thick and gigantic 
vegetation as to render it impenetrable to bulky animals. In 
these regions man is considered as a being not congenial to 
such a state of nature. The earth there luxuriates in its 
gigantic palms, fern-trees, club-mosses, and various rank and 
succulent plants. The crocodiles, sharks, iguanoes, &c., are 
masters of the rivers; and the jaguar, pecari, tapir, boa, and a 
variety of reptiles, rove and infest the banks, and the high 
grass surrounding the lagoons, nothing impeding their increase; 
and are almost the sole possessors of the country — as in the 
imagined primaeval world — without fear and without danger of 
being disturbed by any human being. Were this region to sink 
320 feet, the whole surface would be covered by the Atlantic 
ocean, and the eastern declivity of the Andes would become 
again what it was before, a shore of the ocean. In many parts 
of the country are large plains partially covered with gravel, 
