In many cafes, I have found the disease, in fpite of remedies of all kinds, continue for many months; but I have also found it often readily yield to tonic remedies, fuch as the Peruvian bark, and chalybeates.

The late Dr De Haen found feveral

per

fons labouring under this disease cured by the application of electricity.

SECT.

SECT II.

OF THE SPASMODIC AFFECTIONS OF THE VITAL FUNCTIONS.

CHA P. IV*.

OF THE PALPITATION OF THE HEART.

T

MCCCLV.

HE motion thus named is a contraction or fyftole of the heart, that is performed with more rapidity, and generally

* Though I have thought it proper to divide this book into fections, I think it neceffary, for the convenience of references, to number the chapters from the beginning.

rally also with more force, than usual; and when at the fame time the heart ftrikes with more than ufual violence against the infide of the ribs, producing often a confiderable found.

MCCCLVI.

This motion, or palpitation, is occafioned by a great variety of causes, which have been recited with great pains by Mr Senac and others, whom, however, I cannot follow in all the particulars with fufficient difcernment, and therefore fhall here only attempt to refer all the several cafes of this disease to a few general heads.

MCCLVII.

The firft is of those arifing from the application of the ufual ftimulus to the

heart's

heart's contraction; that is, the influx of the venous blood into its cavities, being made with more velocity, and therefore, in the fame time, in greater quantity than ufual. It seems to be in this manner that violent exercise occafions palpitation.

MCCCLVIII.

A fecond head of the cafes of palpitation, is of those arifing from any resistance given to the free and entire evacuation of the ventricles of the heart. Thus a ligature made upon the aorta occafions palpitations of the most violent kind. Similar refiftances, either in the aorta or pulmonary artery, may be readily imagined; and fuch have been often found in the dead bodies of perfons who, during life, had been much affected with palpitations.

To this head are to be referred all thofe

cafes

cafes of palpitation arifing from causes producing an accumulation of blood in great veffels near to the heart.

the

MCCCLIX.

A third head of the cafes of palpitation, is of those arifing from a more violent and rapid influx of the nervous power into the mufcular fibres of the heart. It is in this manner that I fuppose various caufes acting in the brain, and particularly certain emotions of the mind, occafion palpitation.

MCCCLX.

A fourth head of the cafes of palpitation, is of those arifing from caufes producing a weakness in the action of the heart, by diminishing the energy of the brain with respect to it. That fuch causes

ope

rate