From hence I conclude, that both the cold and hot fits of fever are necessary consequences of the perpetual and incessant action of the arterial and glandular system; since those muscular fibres and those organs of sense, which are most frequently exerted, become necessarily most affected both with defect and accumulation of sensorial power:  and that hence fever-fits are not an effort of nature to relieve herself, and that therefore they should always be prevented or diminished as much as possible, by any means which decrease the general or partial vascular actions, when they are greater, or by increasing them when they are less than in health, as described in Sect.  XII. 6. 1.

Thus have I endeavoured to explain, and I hope to the satisfaction of the candid and patient reader, the principal symptoms or circumstances of fever without the introduction of the supernatural power of spasm.  To the arguments in favour of the doctrine of spasm it may be sufficient to reply, that in the evolution of medical as well as of dramatic catastrophe,

  Nec Deus intersit, nisi dignus vindice nodus inciderit.—­HOR.

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SECT.  XXXIII.

DISEASES OF SENSATION.

I. 1. Motions excited by sensation.  Digestion.  Generation.  Pleasure of existence.  Hypochondriacism. 2. Pain introduced.  Sensitive fevers of two kinds. 3. Two sensorial powers exerted in sensitive fevers.  Size of the blood.  Nervous fevers distinguished from putrid ones.  The septic and antiseptic theory. 4. Two kinds of delirium. 5. Other animals are less liable to delirium, cannot receive our contagious diseases, and are less liable to madness. II. 1. Sensitive motions generated. 2. Inflammation explained. 3. Its remote causes from excess of irritation, or of irritability, not from those pains which are owing to defect of irritation.  New vessels produced, and much heat. 4. Purulent matter secreted. 5. Contagion explained. 6. Received but once. 7. If common matter be contagious? 8. Why some contagions are received but once. 9. Why others may be received frequently.  Contagions of small-pox and measles do not act at the same times.  Two cases of such patients. 10. The blood from patients in the small-pox will not infect others.  Cases of children thus inoculated.  The variolous contagion is not received into the blood.  It acts by sensitive association between the stomach and skin. III. 1. Absorption of solids and fluids. 2. Art of healing ulcers. 3. Mortification attended with less pain in weak people.

I. 1.  As many motions of the body are excited and continued by irritations, so others require, either conjunctly with these, or separately, the pleasurable or painful sensations, for the purpose of producing them with due energy.  Amongst these the business of digestion supplies us with an instance:  if the food, which we swallow, is not attended with agreeable sensation, it digests less perfectly; and if very disagreeable sensation accompanies it, such as a nauseous idea, or very disgustful taste, the digestion becomes impeded; or retrograde motions of the stomach and oesophagus succeed, and the food is ejected.