[ *7 ] 
Powers, till they have attain'd their former Situa- 
tions, or, in other Words, till the Spring has reco- 
ver'd its former Shape* 
XXXVI. 
The fame Principles of Attra&ion and Repulfion 
are the Caufe of Reftitution or Elafticity in all other 
kind of Bodies. When a mufcular Fibre isftretched 
out longer than ufual, it is moft certain that fome of 
its component Particles muft flip upon or by one 
another, or elfe be removed at exceeding fmall Di* 
fiances from each other 5 fo that if the imprfcfled 
Force be too violent, if the Tenfion be carried fo 
far as to disjoin a great Number of the component 
Particles beyond their Sphere of Attraction, the Fi- 
bre will continue to grow weaker and weaker till it 
breaks : But it is, as evident, on the other Side, that 
when a ftretched-out Fibre does not break, but re- 
tra&s itfelf into its former Shape and Dimenfions, 
upon the Removal of the extending Power, the Par- 
ticles which were difplaced return again to their 
proper Pofitions, merely by the means of their at- 
tractive Virtue* 
XXXVII. 
Now all this being fo agreeable to thofe Laws of 
Nature which that divine Man Sir Ifaac Newton 
has difeover'd to us, I think we have good Reafon 
to conclude it to be the true Caufe of Elafticity in the 
animal Fibres. 
C 
XXXVIII, 
