# To W. R. Greg   31 December 1878

Down | Beckenham

Dec 31, 1878

My dear Mr Greg,

Your son seems to believe that ice has been made lighter than water, as otherwise it would have sunk & whole pools or seas have been frozen into a solid mass. But melted bismuth when cooling & solidifying expands largely (by $\frac{1}{32}$ of its bulk) & of course floats, is this a special adaptation? It is much more wonderful & apparently unique case that solid bismuth if subjected to an enormous pressure becomes of less specific gravity; if this lightness had been of any use to man, assuredly it would have been called a special adaptation. But I shall weary you, & I remain, my dear Mr Greg

Yours sincerely | Charles Darwin

## Summary

Discusses a chapter on design, written by WRG’s son [Percy Greg, The devil’s advocate (1878)]. Comments on the younger Greg’s criticisms of natural selection and evolution.

## Letter details

Letter no.
DCP-LETT-11812
From
Darwin, C. R.
To
Greg, W. R.
Sent from
Down
Source of text
American Philosophical Society (557)
Physical description
5pp