FORMVL DIFFERENTIALIVM. 189 



^^Q\ dV\ 

 -W^-^^dJ^ 



^v"- (.l^v.) = ^77-) - (77- )^^.T^ - ^^ 



/VII /RVII y^Q/// ^p/ 



__ ^Q^ dV^ 

 '^^dydz^^^dz^ 

 /^viii /RVi" dd(^^ dV 



^^- ^dxdydz^ -^dz ^ ^dz ^^^d z ^ 



etc. etc. 



44.. Si igitur formula V d x dy d z ita fit 

 comparata , vt eius integrale triplicatum Z non in- 

 voluat , nifi quantitates finitas x^ y^ z et v feu fi 

 fuerit : 



dT.zzidx-^-^dy-^-^Ldz-^-vdio 



criteria integrabilitatis formulis § antecedcntis a II 

 ad XX nihilo aequatis continebuntur , nam pro hoc 

 cafu liquet omncs 'tt, k et ^ euanefcere. Vt vcro 



A a 3 haec 



