partibus infidelium_. I am now occasionally horrified to think
how little I ever knew or cared about medicine as the art of
healing. The only part of my professional course which
really and deeply interested me was physiology, which is
the mechanical engineering of living machines; and,
notwithstanding that natural science has been my proper
business, I am afraid there is very little of the genuine
naturalist in me. I never collected anything, and species
work was always a burden to me; what I cared for was the
architectural and engineering part of the business, the
working out the wonderful unity of plan in the thousands
and thousands of diverse living constructions, and the
modifications of similar apparatuses to serve diverse ends.

One or two typical extracts may be given from the _Journal_, which
opens with a quotation from Novalis: "Philosophy can bake no bread;
but it can prove for us God, freedom, and immortality. Which, now, is
more practical, Philosophy or Economy?" Later comes a quotation from
Lessing, which involved a cardinal principle that he claimed for
himself, and demanded of his pupils: accept no authority without
verifying it for yourself:--

I hate all people who want to found sects. It is not error,
but sects--it is not error, but sectarian error, nay, and even
sectarian truth, which causes the unhappiness of mankind.

Electricity interests him specially; among other experiments,
while theorizing upon them, he makes a galvanic battery "in view
of experiment to get crystallized carbon: got it deposited, but not
crystallized."