se new motions are of a peculiar kind, tending to distend the old, and
to produce new fibres, and thence to elongate the straight muscles, which
serve locomotion, and to form new vessels at the extremities or sides of
the vascular muscles.

2. Thus the pleasurable sensations produce an enlargement of the nipples of
nurses, of the papillae of the tongue, of the penis, and probably produce
the growth of the body from its embryon state to its maturity; whilst the
new motions in consequence of painful sensation, with the growth of the
fibres or vessels, which they occasion, are termed inflammation.

Hence when the straight muscles are inflamed, part of their tendons at each
extremity gain new life and sensibility, and thus the muscle is for a time
elongated; and inflamed bones become soft, vascular, and sensible. Thus new
vessels shoot over the cornea of inflamed eyes, and into scirrhous tumours,
when they become inflamed; and hence all inflamed parts grow together by
intermixture, and inosculation of the new and old vessels.

The heat is occasioned from the increased secretions either of mucus, or of
the fibres, which produce or elongate the vessels. The red colour is owing
to the pellucidity of the newly formed vessels, and as the arterial parts
of them are probably formed before their correspondent venous parts.

3. These new motions are excited either from the increased quantity of
sensation in consequence of greater fibrous contractions, or from increased
sensibility, that is, from the increased quantity of sensorial power in the
moving organ. Hence they are induced by great external stimuli, as by
wounds, broken bones; and by acrid or infectious materials; or by common
stimuli on those organs, which have been some time quiescent; as the usual
light of the day inflames the eyes of those, who have been confined in
dungeons; and the warmth of a common fire inflames those, who have been
previously exposed to much cold.

But these new motions are never generated by that pain, which arises from
defect of stimulus, as from hunger, thirst, cold, or inanition, with all
those pains, which are termed nervous. Where these pains exist, the motions
of the affected part are lessened; and if inflammation succeeds, it is in
some distant parts; as coughs are caused by coldness and moisture being
long applied to the feet; or it is in consequence of the renewal of the
stimulus, as of heat or food, which excites our organs into stronger