Lewis'
explanation is the more correct one. I refer to my own conclusions only
because they were formed quite independently ; for at that time
abstracts merely of Professor Lewis' papers had been published, and
from these I had formed the impression that the name ' kimberlite'
designated the serpentinous fragments which were embedded in the
breccia, and not the rock itself. But whatever be the ultimate result
of that part of the inquiry, this would not necessarily affect my
friend's views as to the genesis of the diamond—viz. by the action of
an extremely basic rock upon carbonaceous material—or diminish the
value of his elaborate researches into the structure and mineral
composition of its matrix.
There
remains only the pleasant duty of returning, on behalf of Mrs. Lewis
and for myself, most hearty thanks to two friends: to J. J. H. Teall,
Esq., F.E.S., who has most kindly taken the admirable micro-photographs
of the slices of the Kimberley and the Kentucky rock, in order to
illustrate this work; and to Professor Eosenbusch, who has been so good
as to read and criticise the proofs. Only those who, like the editor,
have learned from experience of his books the rich stores of his
mineralogical and petro-graphical knowledge can fully appreciate the
value of his generous assistance in putting on record some of the work
produced by one who studied in his laboratory at Heidelberg.
T. G. BONNEY.
