Whereas in the doftrine of Percuffion feveral things are to be accurately 
diftinguifht, as the Force percujfive, the Motion, or the Velocity ofthePer- 
cuffion, and the Ref fiance of the Body per cuffed { and then an Eftimate 
to be made of the Proportion of thofe three to one another : ThisAuthour 
pretends to have both aftigned that difference, and demonftrated the P ro° 
portion Adding, that 'though GaliUo faw and acknowledged (vid. at the 
End of his fourth Dialogue Be Motu VrojeStorumfX^t the Force ofVercuJfi- 
e# was Infinite, or (rather) unlimited^ yet he there referred difcourfing up- 
on that Argument to another opportunity • which not having been per- 
formed by him (Tor ought could be found by any of his writings, either 
Printed or Manufcript, which latter were purpofely fearched after his death 
to find fuch a difcourfe) our Authour pretends, that that Propoficion con- 
cerning the Jnfinitenefs of the force of Percujfion, not having been yet demon- 
Prated by any, he hath in this Book^ refumed the whole matter concerning 
Pf rcuffion^ and dearly demonftrated the true and genuine Nature of it, its 
Gaufe, Proprieties andEffe&s. In the doing of which, he taketh occafion 
to difcourfe alfo of Gravity , Magnetifme, Tremor of Bodies , Pendulums , &c. 
All which, whileft the Reader is confidering, the Authour tells him, that he 
is making ready his other Books concerning the Motions of Animals,, 
IV. NIC. STENONIS MVSCVLl BE SC RIFT 10 GEO ME- 
TRIC A, Florentine in 40. An. 1667. 
The Author of this ifa^declareth, that his defign in compofing it was, 
to fhew,that in a Mufcle neither th e Parts of it can be diftin&ly named- nor 
its Motion duely confide t’d, unlefs the Dodrine thereof become a part of 
the Mathematicks. And he is of opinion, that there is no other caufe of 
the many Errors, which fpoil the Hiftory concerning th & Humane Body 
than that Anatomy hath hitherto difdaind the Lotos of the Mathematic 4 f. 
And therefore inviteth thofe that are ftudious in that part of Philofophy , to 
confider, that bur Body is an Engine fnade up of a thoufand fubordinate 
Engins, whofetrue knowledge whoever thinks that it can be inveftigited 
without Mathematical aftiftance,muft alfo think, that there is matter with- 
out Extenfim, and Body without Figure. 
Hereupon he ftiews, that the very Fabric^ of the Mufcles impofetha kind of neceffity 
upon confidering Writers to explicate them Mathematically : In conformity whereunto 
he pretends to have found, that in every Mufcle there is One Par allelepiped of Fleih, 
and Two Tetragonal Prifmesoi Tendons; defining a Mufcle to be a Body compofedof 
divers feries’s or ranks of Fibers equal, like, and parallel among themfelves, and io im- 
mediately placed upon one another, that whole ranks are congruous to whole ranks. Here 
be explains the Dimenfions of a Mufcle, its Contradion, and Strength, and adds that the 
fife of this new difeoyery of the ftrudure of the Mufcles, is, to demonftrate. That they 
tniy fwell in their Contradion without the Acceflion of new matter, 
He fubjoyns a Letter to Monfieur Tkevenot, in which, among other things, he ailed ^es 
feveral Experiments, to ihew, that the Motion of the Heart is like the Motion 3 Q £ 
Muftiesi and aofwcrs thofe, who pretend that the true Fabrickof the Hurt hath already 
tc«a 
