186 ELIZABETH CARY AGASSIZ 
reached me yesterday. . . . All these short biographies 
of Louis (especially if they come from any one fa- 
miliar with the whole field of scientific investigation 
in his department) help me in my work. They serve 
to bind together in a compact form the salient points 
of his life for which the materials in my hands 
afford such ample and varied illustration. I think 
I wrote you that I had now completed what I consider 
as the first period — including boyhood and youth, 
closing with his return to Switzerland from Munich 
in 1830-1831....On my return to Cambridge in 
October I hope to begin the critical reading of it 
with Mr. Longfellow. You know how warmly he was 
attached to Louis, and I could have no better adviser 
or guide in the matter of literary criticism or in the 
final selection and sorting of material. But while I 
go on very steadily with my work and consider it 
fairly advanced (since much of the material belonging 
to later periods is also partially prepared), I hope 
his friends and especially his nearest family — his 
sisters — will not feel disappointed if I defer all 
thought of publication for the present. Were the 
work completed, I am daily more convinced that 
some years had better pass before its appearance. It 
seems to me much better that time should mellow 
the crude and often prejudiced appreciations of a 
distinguished man’s life and work, before the final 
word is spoken about it. My feeling about this does 
not diminish my industry, but I should like when 
the book is done to put it away and let it ripen in 
the dark for a while — not without hope that when 
