362  Mr.  milner  on  the  Communication  of 
fprings  a£t,  will  always  generate  equal  forces  in  the  bo- 
dies according  to  his  own  definition  of  that  term,  he  talks 
more  inconfiftently  than  I have  obferved  him  to  do:  on 
the  contrary,  if  I could  find  that  he  has  anfwered  this 
famous  argument  (which  Dr.  jurin  propofed  over  again 
in  Phil.  Tranf.vol.XLin.  with  aconditional  promifeof  em- 
bracing the  Leibnitzian  dodtrine)  by  limply  faying,  that 
fprings  he  confiders  as  motive  forces,  or,  when  the  bodies 
are  equal,  as  accelerating  forces ; and  that  their  actions 
are  equal,  when  in  equal  times  they  generate  equal  velo- 
cities, but  not  necelfarily  equal  forces,  in  the  equal  bo- 
dies; I fhould  not  make  the  leaft  fcruple  to  own  that  I 
thought  his  reafoning  folid  and  conclufive,  and  his  dif- 
tindtions  a full  anfvver  to  every  objection  of  that  fort/^. 
case  the  third.  The  two  preceding  cafes  are  cu- 
rious examples  of  the  force  of  prejudice  and  party-fpirit. 
In.  the  latter  particularly  it  does  not  appear  that  j.  ber- 
(f)  No  doubt  MAp.LAURiN  refers  to  the  following  paiTage  of  Bernoulli, 
C(  La  force  du  choc,  ou  de  l’a£lion  des  corps  les  uns  fur  les  autres,  depend  unique- 
u ment  de  leurs  vitefles  refpedtives;  or  il  eft  Yifible  que  les  vitefles  refpe&ives 
des  corps  ne  changent  pas  avant  le  choc,  foit  que  le  plan  ou  l’efpace  qui  les 
contient  foit  fans  mouvement,  foit  quhl  fe  meuve  uniformement,  fuivant  une 
“ direction  donnee,  les  vitefles  refpe£tives  feront  done  encore  les  memes  apres 
cc  le  choc.” 
This  quotation  puts  the  matter  beyond  difpute.  It  is  plain,  Bernoulli, 
though  he  does  make  ufe  of  the  word  action,  is  only  fpeaking  of  the  motion  loft 
or  communicated,  and  the  relative  velocities  of  the  bodies:  there  is  not  the 
tnoft  did  ant  hint  at  the  change  in  their  abfolute  forces. 
NOULLI 
