This irregular action is, in other words, a _convulsion_ in the sanguiferous, but more obviously, in the arterial system. That this is the case I infer from the strict analogy between symptoms of fever, and convulsions in the nervous system. I shall briefly mention the particulars in which this analogy takes place. 1. Are convulsions in the nervous system preceded by debility? So is the convulsion of the blood-vessels in fever. 2. Does debility induced on the whole, or on a part only, of the nervous system, predispose to general convulsions, as in tetanus? So we observe debility, whether it be induced on the whole or on a part of the arterial system, predisposes to general fever. This is obvious in the fever which ensues alike from cold applied to every part of the body, or from a stream of cold air falling upon the neck, or from the wetting of the feet. 3. Do tremors precede convulsions in the nervous system? So they do the convulsion of the blood-vessels in fever. 4. Is a coldness in the extremities a precursor of convulsions in the nervous system? So it is of fever. 5. Do convulsions in the nervous system impart a jerking sensation to the fingers? So does the convulsion of fever in the arteries, when felt at the wrists. 6. Are convulsions in the nervous system attended with alternate action and remission? So is the convulsion of fever. 7. Do convulsions in the nervous system return at regular and irregular periods? So does fever. 8. Do convulsions in the nervous system, under certain circumstances, affect the functions of the brain? So do certain states of fever. 9. Are there certain convulsions in the nervous system which affect the limbs, without affecting the functions of the brain, such as tetanus, and chorea sancti viti? So there are certain fevers, particularly the common hectic, which seldom produces delirium, or even head-ach, and frequently does not confine a patient to his bed. 10. Are there local convulsions in the nervous system, as in the hands, feet, neck, and eye-lids? So there are local fevers. Intermittents often appear in the autumn with periodical heat and pains in the eyes, ears, jaws, and back. 11. Are there certain grades in the convulsions of the nervous system, as appears in the hydrophobia, tetanus, epilepsy, hysteria, and hypochondriasis? So there are grades in fevers, as in the plague, yellow fever, small-pox, rheumatism, and common remitting and intermitting fevers. 12. Are nervous convulsions most apt to occur in infancy? So are fevers. 13. Are persons once affected with nervous convulsions frequently subject to them through life? So are persons once affected with fever. The intermitting fever often returns with successive springs or autumns, and, in spite of the bark, sometimes continues for many years in all climates and seasons.