37<S DE PRINCIPIIS 



A^-hHS^-HFGzrK reperietur per KK diui- 

 dendo : 



(^4)=?(AP+HQ+FR)-4(A(ffi)+H(^Ji) + F(li|)) 



fimilique modo elicitur : 



( ^-|-)-^(DP+BQ.+IR)-4(D(|ff)+B(li?)+ 1 {^)} 



( i| ) - ? (GP+EQ+CR) - Ji (G{^) +E(|^) +C(^-^^'). 



Multiplicctur porro prima per dX, fecunda per 

 d Y , tertia per d Z j vt obtineatur differentiale 

 preffionis p^ fi tempu^ t conftans ftatuatur , et cum 

 in eadem hypothefi fit : 



AdX-^DdY+GdZ—dx', H^X-fB^Y+E^2— ^^ et 



fdX+ldY-^-CdZzzdz 



noftrae tres aequationes in hanc vnam coalefcent : 



dpzzqi?dxi(ldy+Kdz)^^^{dx{'^} + dj{'/^n+^z(^^^ 



in cuius integratione tempus ? pro conftante eft 

 habendum. -^ ^ 



C o r o 1 1. I. 



120. Cum x^ y^ z fint fundiones ipfarum 

 X, Y, Z et ?, fi ponamus differentiale tompletum 

 dx-AdX'+-lL>dY-\-QdZ-^Ldt crit (li^)=:iL 

 ideoque (^^) — (^) , loco d x autem in hac ae- 



quatione fcribi oportet KdX-\-l)dY^QdZ 

 quia in ea tempus conftans aflumitur. 



Coroll 



