The term Shaking Palsy is evidently inapplicable to the first of these cases, which appears to have belonged more properly to the genus _Convulsio_, of Cullen, or to _Hieranosos_ of Linnæus and Vogel[10]. [Footnote 10: Corporis agitatio continua, indolens, convulsiva, cum sensibilitate.—_Linn._ Agitatio corporis vel artuum convulsiva continua, chronica, cum integritate sensuum.—_Vogel._ This genus is resolved by Cullen into that of Convulsio. _Synops. Nosol._ 1803. Dr. Macbride has given a very interesting and illustrative case of this disease. “Hieranasos, or Morbus Sacer, so called, as being vulgarly supposed to arise from witchcraft, or some extraordinary celestial influence, is a distinct genus of disease, though a very uncommon one; the author once had an opportunity of seeing a case. The patient was a lad about seventeen, who at that time had laboured under this extraordinary disease for more than twelve years. His body was so distorted, and the legs and arms so twisted round it, by the continued convulsive working, that no words can give an adequate idea of the oddity of his figure; the agitation of the muscles was perpetual; but in general he did not complain of pain nor sickness; and had his senses perfectly, insomuch that he used to assist his mother, who kept a little school, in teaching children to read.” _A methodical Introduction to the Theory and Practice of Physic. By David Macbride, M.D. p. 559._] The latter appears to be referable to that class of proteal forms of disease, generated by a disordered state of primæ viæ, sympathetically affecting the nervous influence in a distant part of the body. Unless attention is paid to one circumstance, this disease will be confounded with those species of passive tremblings to which the term Shaking Palsies has frequently been applied. These are, _tremor temulentus_, the trembling consequent to indulgence in the drinking of spirituous liquors; that which proceeds from the immoderate employment of tea and coffee; that which appears to be dependent on advanced age; and all those tremblings which proceed from the various circumstances which induce a diminution of power in the nervous system. But by attending to that circumstance alone, which has been already noted as characteristic of mere tremor, the distinction will readily be made. If the trembling limb be supported, and none of its muscles be called into action, the trembling will cease. In the real Shaking Palsy the reverse of this takes place, the agitation continues in full force whilst the limb is at rest and unemployed; and even is sometimes diminished by calling the muscles into employment. CHAP. IV. PROXIMATE CAUSE—REMOTE CAUSES—ILLUSTRATIVE CASES.