345 
sea.” He goes on to establish this idea by a reference to 
other rivers, and especially by a description of the Arabian 
Gulf, into which, he says, if the Nile were turned, it would fill 
ifc up within twenty thousand, or even within ten thousand 
years. Herodotus gives a number of other reasons for his 
belief that the sea once flowed over the space now occupied 
by Egypt; among which is the fact that “ shells are found on 
the mountains.” He says, “ that a saline humour forms on 
the surface, so as even to corrode the pyramids, and that this 
mountain, which is above Memphis, is the only one in Egypt 
which abounds in sand ; add to which that Egypt in its soil is 
neither like Arabia or its confines, nor Libya, nor Syria 
(Syrians occupy the sea-coast of Arabia), but is black and 
crumbling, as if it were mud and alluvial deposit, brought 
down by the river from Ethiopia,, whereas we know that the 
earth of Libya is reddish and somewhat more sandy ; and that 
of Arabia and Syria is more clayey and flinty.” It is very 
clear, we think, from these true ideas of this author regarding 
the basin of the Nile, that he was accustomed to a certain 
extent to follow out his observations of the surface of the 
earth, in true geological reasoning. 
But we pass from the Greeks to the Homans, to give the 
ideas of another truly representative man. So far as the 
collection of facts and correct reasoning on these are concerned, 
Pliny is our best ancient writer on geology. This does not 
arise from his own observation of the structure of the earth, 
so much as from the wonderful acquaintance which he displays 
with the works of other authors. Herodotus was a traveller, 
and observed with his own eyes the facts which he- narrated. 
Pliny gathered sheaves of information from the labours of all 
reapers in the field of knowledge. 
It is in connection with earthquakes that this author gives 
us his best geology. Speaking of these, he says that “the 
earth is shaken in various ways, and wonderful effects are 
produced ; in one place the walls of cities are thrown down, 
and in others swallowed up by a deep cleft ; sometimes great 
masses of earth are heaped up, and rivers forced out, some- 
times even flame and hot springs, and at others the course 
of rivers is turned.” “ There is no doubt,” he says, “ that 
earthquakes are felt by persons on shipboard, as they are 
struck by a sudden motion of the waves, without these being- 
raised by any gust of wind.” Then he notes the important 
truth that “ inundations of the sea take place at the same 
time with earthquakes ; the water being- impregnated with the 
same spirit, and received into the bosom of the earth which 
subsides.” “The same cause produces an increase of the land; 
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