Where did Terrestrial Life Begin?

DR. MACFIE'S letter (NATURE, January 26, p. 107) accepts the common idea that the surface of the earth was formerly very hot-an assumption which is probably not well founded. If the earth was formed by accumulation of meteoric matter, it began its existence as a cold body the interior of which afterwards became heated by condensation, aided by atomic disintegration, while its surface was kept at a moderate temperature by radiation. It is difficult to believe that a globe so small, comparatively, as the earth could produce enough heat to raise its surface temperature anywhere near to the melting point; all igneous rocks are probably formed at some distance beneath the surface.