III.  The seat of rheumatism is in the membranes, or upon them; but there are three very distinct diseases, which commonly are confounded under this name.  First, when a membrane becomes affected with torpor, or inactivity of the vessels which compose it, pain and coldness succeed, as in the hemicrania, and other head-achs, which are generally termed nervous rheumatism; they exist whether the part be at rest or in motion, and are generally attended with other marks of debility.

Another rheumatism is said to exist, when inflammation and swelling, as well as pain, affect some of the membranes of the joints, as of the ancles, wrists, knees, elbows, and sometimes of the ribs.  This is accompanied with fever, is analogous to pleurisy and other inflammations, and is termed the acute rheumatism.

A third disease is called chronic rheumatism, which is distinguished from that first mentioned, as in this the pain only affects the patient during the motion of the part, and from the second kind of rheumatism above described, as it is not attended with quick pulse or inflammation.  It is generally believed to succeed the acute rheumatism of the same part, and that some coagulable lymph, or cretaceous, or calculous material, has been left on the membrane; which gives pain, when the muscles move over it, as some extraneous body would do, which was too insoluble to be absorbed.  Hence there is an analogy between this chronic rheumatism and the diseases which produce gravel or gout-stones; and it may perhaps receive relief from the same remedies, such as aerated sal soda.

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SECT.  XXVII.

OF HAEMORRHAGES.

I. The veins are absorbent vessels. 1. Haemorrhages from inflammation.  Case of haemorrhage from the kidney cured by cold bathing.  Case of haemorrhage from the nose cured by cold immersion. II. Haemorrhage from venous paralysis.  Of Piles.  Black stools.  Petechiae.  Consumption.  Scurvy of the lungs.  Blackness of the face and eyes in epileptic fits.  Cure of haemorrhages from venous inability.

I. As the imbibing mouths of the absorbent system already described open on the surface, and into the larger cavities of the body, so there is another system of absorbent vessels, which are not commonly esteemed such, I mean the veins, which take up the blood from the various glands and capillaries, after their proper fluids or secretions have been separated from it.

The veins resemble the other absorbent vessels; as the progression of their contents is carried on in the same manner in both, they alike absorb their appropriated fluids, and have valves to prevent its regurgitation by the accidents of mechanical violence.  This appears first, because there is no pulsation in the very beginnings of the veins, as is seen by microscopes; which must happen, if the blood was carried into them by the actions of the arteries.  For though the