onvulsions, first of
the muscles, and then of the ideas, returned twice a day for several weeks;
and were at length removed by great doses of opium, after a great variety
of other medicines and applications had been in vain experienced. This lady
was subject to frequent relapses, once or twice a year for many years, and
was as frequently relieved by the same method.

Miss W----, an elegant young lady, with black eyes and hair, had sometimes
a violent pain of her side, at other times a most painful strangury, which
were every day succeeded by delirium; which gave a temporary relief to the
painful spasms. After the vain exhibition of variety of medicines and
applications by different physicians, for more than a twelvemonth, she was
directed to take some doses of opium, which were gradually increased, by
which a drunken delirium was kept up for a day or two, and the pains
prevented from returning. A flesh diet, with a little wine or beer, instead
of the low regimen she had previously used, in a few weeks completely
established her health; which, except a few relapses, has continued for
many years.

9. Lastly, as we advance in life all the parts of the body become more
rigid, and are rendered less susceptible of new habits of motion, though
they retain those that were before established. This is sensibly observed
by those who apply themselves late in life to music, fencing, or any of the
mechanic arts. In the same manner many elderly people retain the ideas they
had learned early in life, but find great difficulty in acquiring new
trains of memory; insomuch that in extreme old age we frequently see a
forgetfulness of the business of yesterday, and at the same time a
circumstantial remembrance of the amusements of their youth; till at length
the ideas of recollection and activity of the body gradually cease
together,--such is the condition of humanity!--and nothing remains but the
vital motions and sensations.

VI. 1. In opposition to this doctrine of the production of our ideas, it
may be asked, if some of our ideas, like other animal motions, are
voluntary, why can we not invent new ones, that have not been received by
perception? The answer will be better understood after having perused the
succeeding section, where it will be explained, that the muscular motions
likewise are originally excited by the stimulus of bodies external to the
moving organ; and that the will has only the power of repeating the motions
thus exci