166 *The consequences of the

forate any part of the body, opposing its di-rection, like a ball out of a gun, and so leavethe body quite, without performing the de-signed effect. Borelli calculates that when aman extends his arm, and upon the extre-mity of his four fingers supports as great aweight as he can in that posture, the forcethat is exerted in the muscles to support thisweight, is more than seventy thousand timesgreater than the weight itself, whatever thisis(Æ). But it is impossible that a force equalto this could be directly impressed on a part,that almost escapes observation, without hav-ing the effect just now mentioned. Whenceit is evident, That all the force is not itft'prejfed on the first moved parts (animal Spi"rits, v. g.); and that all that it doth is ontyto give scope to a jar greater power to b?exerted ; and that this immaterial power iSexerted in fubordhiation to the will , or co -operates with it.

XXIII. This Author, who was thethat discovered that the force exerted wi>h jrlthe body so enormously exceeds the wci§^

(i) Idem j Part. i. Prop. 45, 82 & 124.

to