48 
MEMOIR OF LAMARCK. 
at last obliged to renounce the labour as fruitless, 
satisfied that, however important it would be to 
foresee the -state of the weather, it depends on 
causes far too remote and complex to be made the 
subject of calculation. 
Speculations of an analogous character regarding 
the formation of the globe and the changes which it 
has undergone, were laid before the public, in 1802, 
in a work entitled “ Hydrogeology, or Researches 
on the Influence exerted by Water on the Surface 
of the terrestrial Globe,” &c. &c. Ilis opinions rest 
on the assumption that all composite minerals are 
the remains of living beings. According to him, 
the seas are continually' hollowing out their bed in 
consequence of being unceasingly agitated by the 
tides, produced by the action of the moon ; in pro- 
portion as the bed deepens in the crust of the earth, 
it necessarily follows that their level lowers, and 
their surface diminishes ; and thus the dry land, 
formed by the delris of living creatures, is more 
and more disclosed. As the land emerges from the 
sea, the water from the clouds forms currents upon 
its surface, by which it is rent and excavated, and 
divided into valleys and mountains. With the ex- 
ception of volcanoes, our steepest and most elevated 
ridges have formerly belonged to plains, even their 
substance once made a part of the bodies of animals 
and plants ; and it is in consequence of being so 
long purified from foreign principles that they are 
reduced to a siliceous nature. But running waters 
furrow them in all directions, and carry their mate- 
