he functions of
the part affected: on the skin and bronchiae, where this secretion ought
naturally to evaporate, it becomes so viscid as to adhere to the membrane;
on the tongue it forms a pellicle, which can with difficulty be scraped
off; produces the scurf on the heads of many people; and the mucus, which
is spit up by others in coughing. On the nostrils and fauces, when the
secretion of these capillary glands is increased, it is termed simple
catarrh; when in the intestines, a mucous diarrhoea; and in the urethra, or
vagina, it has the name of gonorrhoea, or fluor albus.

4. When these capillary glands become inflamed, a still more viscid or even
cretaceous humour is produced upon the surfaces of the membranes, which is
the cause or the effect of rheumatism, gout, leprosy, and of hard tumours
of the legs, which are generally termed scorbutic; all which will be
treated of hereafter.

II. 1. The whole surface of the body, with all its cavities and contents,
are covered with membrane. It lines every vessel, forms every cell, and
binds together all the muscular and perhaps the osseous fibres of the body;
and is itself therefore probably a simpler substance than those fibres. And
as the containing vessels of the body from the largest to the least are
thus lined and connected with membranes, it follows that these membranes
themselves consisted of unorganized materials.

For however small we may conceive the diameters of the minutest vessels of
the body, which escape our eyes and glasses, yet these vessels must consist
of coats or sides, which are made up of an unorganized material, and which
are probably produced from a gluten, which hardens after its production,
like the silk or web of caterpillars and spiders. Of this material consist
the membranes, which line the shells of eggs, and the shell itself, both
which are unorganized, and are formed from mucus, which hardens after it is
formed, either by the absorption of its more fluid part, or by its uniting
with some part of the atmosphere. Such is also the production of the shells
of snails, and of shell-fish, and I suppose of the enamel of the teeth.

2. But though the membranes, that compose the sides of the most minute
vessels, are in truth unorganized materials, yet the larger membranes,
which are perceptible to the eye, seem to be composed of an intertexture of
the mouths of the absorbent system, and of the excretory ducts of the
capillaries, with their concomitant