examination of the mental field, latterly much in vogue,
which had a different origin. This is the scientific investigation of
the phenomena of hypnotism. This subject was rescued from the hands of
charlatans, rechristened, and subjected to accurate investigation by
Dr. James Braid, of Manchester, as early as 1841. But his results, after
attracting momentary attention, fell from view, and, despite desultory
efforts, the subject was not again accorded a general hearing from
the scientific world until 1878, when Dr. Charcot took it up at
the Salpetriere, in Paris, followed soon afterwards by Dr. Rudolf
Heidenhain, of Breslau, and a host of other experimenters. The value
of the method in the study of mental states was soon apparent. Most
of Braid's experiments were repeated, and in the main his results were
confirmed. His explanation of hypnotism, or artificial somnambulism,
as a self-induced state, independent of any occult or supersensible
influence, soon gained general credence. His belief that the initial
stages are due to fatigue of nervous centres, usually from excessive
stimulation, has not been supplanted, though supplemented by notions
growing out of the new knowledge as to subconscious mentality in
general, and the inhibitory influence of one centre over another in the
central nervous mechanism.

THE BRAIN AS THE ORGAN OF MIND

These studies of the psychologists and pathologists bring the relations
of mind and body into sharp relief. But even more definite in this
regard was the work of the brain physiologists. Chief of these, during
the middle period of the century, was the man who is sometimes spoken of
as the "father of brain physiology," Marie Jean Pierre Flourens, of the
Jardin des Plantes of Paris, the pupil and worthy successor of Magendie.
His experiments in nerve physiology were begun in the first quarter of
the century, but his local experiments upon the brain itself were
not culminated until about 1842. At this time the old dispute over
phrenology had broken out afresh, and the studies of Flourens were
aimed, in part at least, at the strictly scientific investigation of
this troublesome topic.

In the course of these studies Flourens discovered that in the medulla
oblongata, the part of the brain which connects that organ with the
spinal cord, there is a centre of minute size which cannot be injured in
the least without causing the instant death of the animal operated upon.
It may be added that i