rate in producing palpitation, I prefume from hence, that all the feveral caufes mentioned above (MCLXXVII. et seq.), as in this manner producing fyncope, do often produce palpitation. It is on this ground that these two diseases are affections frequently occurring in the fame perfon, as the fame caufes may occafion the one or the other, according to the force of the cause and mobility of the perfon acted upon. It seems to be a law of the human œconomy, that a degree of debility occurring in any function, often produces a more vigorous exertion of the same, or at least an effort towards it, and that commonly in a convulfive manner.

I apprehend it to be the convulsive action, frequently ending in fome degree of a fpafm, that gives occafion to the intermittent pulse fo frequently accompanying palpitation.

MCCCLXI.

MCCCLXI

A fifth head of the cafes of palpitation may perhaps be of those arising from a peculiar irritability or mobility of the heart. This, indeed, may be confidered as a predisponent caufe only, giving occafion to the action of the greater part of the caufes recited above. But it is proper to observe, that this predifpofition is often the chief part of the remote cause; infomuch that many of the caufes producing palpitation would not have this effect but in perfons peculiarly predisposed. This head, therefore, of the cafes of palpitation, often requires to be distinguished from all the reft.

MCCCLXIL

After thus making the feveral cafes and causes of palpitation, I think it neceffary, with

view to the cure of this disease, to observe, that the feveral caufes of it may be again reduced to two heads. The first is, of those confifting in, or depending upon, certain organic affections of the heart itfelf, or of the great veffels immediately connected with it. The fecond is of thofe confifting in, or depending upon, certain affections fubfifting and acting in other parts of the body, and acting either by the force of the caufe, or in confequence of the mobility of the heart.

MCCCLXIII.

With refpect to the cafes depending upon the first set of causes, I muft repeat here what I said with respect to the like cafes of fyncope, that I do not know

any means of curing them. They, indeed, admit of fome palliation, firft, by avoiding every circumftance that may hurry the circula

tion of the blood; and, fecondly, by every means of avoiding a plethoric state of the fyftem, or any occafional turgefcence of the blood. In many of these cafes, bloodletting may give a temporary relief: but in fo far as debility and mobility are concerned, in fuch cases this remedy is likely› to do harm.

MCCCLXIV.

With respect to the cafes depending upon the other fet of caufes, they may be various, and require very different measures: but I can here fay in general, that these cafes may be confidered as of two kinds; one depending upon primary affections in other parts of the body, and acting by the force of the particular caufes; and another depending upon a state of mobility in the heart itself. In the first of these, it is obvious, that the cure of the palpitaB b 2

tion

tion must be obtained by curing the pri mary affection; which is not to be treated of here. In the second, the cure must be obtained, partly by diligently avoiding the occafional causes, partly and chiefly by correcting the mobility of the fyftem, and of the heart in particular; for doing which we have treated of the proper means elfewhere.

CHAP.