c i8z ] 
they do not come into more or lefs Contad in one 
Situation than another. But if we fuppofe the Point 
n in each Spherule to be a Pole with a Force to 
repel all the other Points n in any other Spherule, 
and likewife s another Pole, repelling the other Points 
S-, the Spherules will cohere beft, and be at Reft in 
that Pofition where the Points CjCj are in Contad, 
and n and s at equal Diftances on either Side. For 
if the Spherules be turn'd a little, fo as to bring the 
Points into Contad, as in Fig. 5. the Poles 
being brought nearer, ad againft each other with 
more Force than the Points s, r, which are now far- 
ther off, and confequently drive back the Spherules 
to the Contad at c, c, beyond which continuing their 
Motion, they will go to S' S', Fig. 6 . and fo back- 
wards and forwards, till at laft they reft at f, r, which 
we may call the Voint of c_yEquilihrmin for Reft in 
a Spring. Now there are, belides this, two other 
Joints of zyEqiiilibrmm^ beyond which the Spring 
may break, which are the Points e^e towards w, and 
£,g towards jj fee Fig. 7. that is, when the Spherules 
have their Poles », n brought very near together, the 
mutual Repullion increafes fo, that the Attradion at 
the Contad is not able to hold them, and then they 
muft fly afunder, the Spring breaking. We fuppofe 
the Points e^e-^ fo be the Points of Contad, beyond 
which this muft happen 5 but that if the Contad be 
ever fo little Ihort of it, as between e and the 
Spherules will return to their Contad at r, after 
fomc Vibrations beyond it, as has been already faid. 
This is the Reafon why I call (in one of the Sphe- 
rules) and its correfpondent Point ^ on the other Side 
c, the Toints of eyEqutUbr turn \ for if the Spring be 
bent 
