and Agitatorii, or, as many at present use the terms, into Spafms ftrictly fo called, and Convulfions. I find, however, that many, and indeed most of the diseases to be confidered under our title of Spafmodic Affections, in refpect of Tonic or Clonic contractions, are of a mixed kind: and, therefore, I cannot follow the ufual general divifion; but have attempted another, by arranging the feveral Spafmodic Difeases according as they affect the feveral functions, Animal, Vital, or Natural.

SECT. I.

Of the SPASMODIC AFFECTIONS of the ANIMAL FUNCTIONS.

MCCLIV.

AGREEABLE to the language of the ancients, the whole of the diseases to be treated of in this fection might be termed Spafmi; and many of the moderns continue to apply the term in the fame manner: but I think it convenient to distinguish the terms of Spafm and Convulfion, by ap plying the former, ftrictly to what has been called the Tonic, and the latter, to

what

what has been called the Clonic Spasm There is certainly a foundation for the use of those different terms, as there is a remarkable difference in the state of the con

traction of moving fibres upon different occafions. This I have indeed pointed out before in my treatise of Physiology, but must also repeat it here.

MCCLV.

In the exercife of the several functions of the animal œconomy, the contractions of the moving fibres are excited by the will, or by certain other causes specially appointed by nature for exciting those contractions; and these other causes I name the natural causes. In a ftate of health the moving fibres are contracted by the power of the will, and by the natural caufes only. At the fame time the contractions produced are in force and velocity regulated

by

by the will, or by the circumftances of the natural caufes; and the contractions, wher ther produced by the one or the other, are always foon fucceeded by a state of relaxation, and are not repeated but when the power of the will or of the natural causes is again applied,

MCCLVI.

Such are the conditions of the action of the moving fibres in a state of health; but in a morbid state, the contractions of the muscles and moving fibres ordinarily depending upon the will are excited without the concurrence of the will, or contrary to what the will intends; and in the other functions they are excited by the action of unufual and unnatural causes. In both cafes, the contractions produced may be in two different ftates. The one is, when the contractions are to a more violent de

gree

gree than is ufual in health, and are neither fucceeded by a spontaneous relaxation, nor even readily yield to an extension either from the action of antagonist muscles, or from other extending powers applied. This ftate of contractions is what has been called a Tonic Spasm, and is what I shall name fimply and ftrictly a Spafm. The other morbid state of contractions is, when they are fucceeded by a relaxation, but are immediately again repeated without the concurrence of the will or of the repetition of natural causes, and are at the fame time commonly with refpect to velocity and force more violent than in a healthy ftate. This state of morbid contraction is what has been named a Clonic Spasm, and and what I fhall name fimply and strictly a Convulfion.

In this section I fhall follow nearly the usual divifion of the fpafmodic diseases,