Opuscula. 21 j 
ncs fuperiores . Ab 'xquatione 25/. i-i- „ ~- — m u n , 
quac ftatim fe fe ofFerr , eodem ufurp.ito calculo pervenie- 
mus ad fecundo - diiferenrialem z — gdxdt — d d x ; 
{^d d X =: d z — d s , 3l d d X — d d z> — d d s : ergo % d 
— gdzdt-\-gdsdt — rrddzj — r r d d s: atqui d s ^ , 
Szdds- iLil : igitur z dt^—gdz d t -i- -l- V d ~ rrddn 
- — YdVdt, oux in hunc modum difponatur 
r'^kdVdt-\-zdt'' — gdzdt — t^-ddz — o, Hxc xquatio 
^^Vdt^- 
multiplicanda efi: per ^ , tum addendi & detrahendi termini 
jequales ita , ut termini onmes, excepto fecundo , fmt inte- 
grabiles , hoc modo 
~- ^ V d t-i-z(]^dt^—'g(pdzdt — r^(jpddz ~o. 
•j-(\> Vdt^-i-gz dcpd t-y- r^ dcp d z ■— r^ d cp d z 
■ — r^zddcp~gzd(jpdt 
-\~ r^ z d d 
OmiiTo fecundo termino , fiat integratio 
■^dt ,f(pd V-\- -^dtfpVdt-— g(pzd t-\-r^z d (p — d z — o. 
Secundus terminos divifus per z fiat — o , uc prodeat 
sequatio — (p d t"^ — g d '(p d t -\- r~ d d (p — o . Huj js lacegratio 
dependet a refolutione scquationis — ■ i — -y-«H-;2« — o, 
qux eft hujufmodi n — -r;~y^gg-^4^^' ^-^- ^^^' 
fert ab ilia , quam invenimus in hypotheri poccntix attrahen- 
tis , nifi per hoc , quod terminus ^rr in hac afficitur fi- 
gno -}- , in illa figno — . Quare quum xquatio princeps fit 
omnino eadem tam in potentia atcrahente , quam ih repel- 
lente , conjungemus cafum potentix attrahentis , ubi ^ > 2 r, 
cum hypothefi potentiae rcpellentis fLiibendo 
» = -^±^^^4^4^^» Si^oum fuperius pofitum fub radi- 
Tom. VL E e ce 
