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by the Will, with thefe Animal Spirits, through the 
Nerve to the Mufcle to be moved 5 which caufes the 
firft Tumefcence of the Mufcle: And that the Soul 
has an Imperium *, through the whole Mafs of Blood 
alfo; as is manifeft in the various Paffions of Anger, 
Joy, Love, Bafhfulnefs, <&c. whereby fhe is capable 
of determining the Blood to any Part in a greater 
Quantity than ordinary, and, confequently, to the 
Mufcle to be moved : For, fays he, it is not abfurd 
to imagine, that the fame Idea, which excites ‘the 
Will to move a Mufcle, and the Spirits in the Nerve 
to perform it, in like manner is capable, at the fame 
Inftant, of determining Spirits to the Heart, by the 
Nerve 
* Ir will appear in the next Lecture, that the Soul can have no 
Imperium over the Blood, and only prefides over the voluntary Addons 
of the Body ; for the Heart drives the Blood indiferimiqately to all 
Parts of the Body, for its Welfare, by a propelling Force, which is 
involuntary : Nor can the Motion of the Heart be accelerated im- 
mediately by the Will, but only by fome particular Ad of the Body 
before fuch as an Increafe of Exercile by Running, &c. And as 
£0 thole Paffions of Anger, Bafhfulnefs, Joy, &c. they firft occafion 
quick and irregular Refpiration : This caufes a quicker Motion of the 
Heart, which warms and rarefies the Blood more, whereby it is 
driven with greater Velocity to all Parts, and among them to the 
Cheeks. Thus Blufhing happens, not becaufe the Soul determined 
more Blood than ordinary to them, but becaufe its Momentum is 
mcreafed involuntarily by the Shock or Surprize previous to it : For 
the whole Surface of the Body is affeded in the fame manner, tho’ 
moft apparent in the Cheeks. Hence no Increafe of Blood can be 
determined to one Part more than another j unlefs fome Impedi. 
ment happens to its free Circulation in one Part, or the Refiftance 
becomes lei's in another j which we fhall hereafter fhew. But belidesy 
one would be apt to think, if the Soul had an Imperium over the 
Blood, fhe might as well prevent the Efleds of Poifon, or any other 
Malignity in it, and corred the Mafs ; as immediately determine it 
in a more than ordinary Quantity to any particular Part of the Body, 
