at least I have found it so, to state in what the difference consists.
When we witness any deep emotion, our sympathy is so strongly
excited, that close observation is forgotten or rendered
almost impossible; of which fact I have had many curious proofs.
Our imagination is another and still more serious source of error;
for if from the nature of the circumstances we expect
to see any expression, we readily imagine its presence.
Notwithstanding Dr. Duchenne's great experience, he for a long
time fancied, as he states, that several muscles contracted
under certain emotions, whereas he ultimately convinced himself
that the movement was confined to a single muscle.

In order to acquire as good a foundation as possible, and to ascertain,
independently of common opinion, how far particular movements
of the features and gestures are really expressive of certain states
of the mind, I have found the following means the most serviceable.
In the first place, to observe infants; for they exhibit many emotions,
as Sir C. Bell remarks, "with extraordinary force;" whereas, in after life,
some of our expressions "cease to have the pure and simple source
from which they spring in infancy."[18]

In the second place, it occurred to me that the insane ought to
be studied, as they are liable to the strongest passions, and give
uncontrolled vent to them. I had, myself, no opportunity of doing this,
so I applied to Dr. Maudsley and received from him an introduction
to Dr. J. Crichton Browne, who has charge of an immense asylum
near Wakefield, and who, as I found, had already attended to the subject.
This excellent observer has with unwearied kindness sent me copious
notes and descriptions, with valuable suggestions on many points;
and I can hardly over-estimate the value of his assistance. I owe also,