ive
statements on insufficient data, or suffers from that other vice of not
being able to confess ignorance. The only lectures which impressed me,
as an undergraduate at Cambridge, were those of the late Sir George
Humphry; and his most striking words were confessions of complete
ignorance about many parts of physiology. Here is an instance of an
opposite state of things, of a want of courage. An eminent chemist was
asked why common salt thrown on the fire gives a blue flame. Now the
chemist was a German, and having been brought up in that land of stoves,
probably had not performed an experiment so easily made in the home of
open fires. So he rashly answered, "It does not burn blue, it is
impossible, sodium-salts give a yellow flame." On this my friend fetched
the salt and threw a handful on to the glowing coals--with the result
that the eminent chemist rose up and fled in silence from the room. He
gave an admirable example of how not to behave. He ought not in the
first place to have denied the fact _a priori_, and when he was convicted
he should have been glad to learn.

It has been said that in scientific work accuracy is the most valuable
quality and the hardest to attain. Accuracy alone may strike us as a
dull quality to be so highly rated. When a given result has been
obtained in eleven successive experiments, and fails on the twelfth
occasion, it is the accurate-minded man who makes a wise use of the
failure. It ought to arouse in us a flame of curiosity, lighting in us a
whole posse of theories, which force us to vary our procedure and finally
enable us to solve the difficulty.

Most of us are inclined to treat an unexpected result in a cavalier
spirit, pushing it aside as "only an exception," whereas it should be
received as possibly a personage of distinction in disguise, and not as a
rude disturber of our pet ideas.

A class of experimentalists exists from whom we all suffer--namely,
cooks. How happy we should be if they possessed this lively desire to
understand their own lapses from good cookery! It may be urged in
excuse, that although the essence of cooking is the application of heat
to food, not one cook in a thousand has a thermometer in her oven. I
hope that some of the ladies who have in these laboratories learned to
believe in accuracy, will become missionaries among the ignorant and
insist on this simple reform.

There is a type of accuracy of a very different kind which may become