174- DE LEGE REFRACTIONIS 



mm harum lcgiim phaenomenis maxime fatisfaciat : 

 hacc lcilicet via ad vcritatcm pcrucniendi vel faltem 

 appropinqiiandi tutiflima videtur. 



Problema i. 



19. In hypothcfi rcfracflionis modo mcmora- 

 ta , data refradione media pro tranfitu radiorum 

 quocunquc ex medio alio inahud, definirc refradio- 

 nes extremas, rubram fcilicet et violaceam. 



S o 1 u t i o. 



Concipiantur mcdia quotcunquc diaphana A, 

 B, C, D etc. ita comparata , vt dum radii ex co- 

 rum quouis in fcqucns tranfcunt , rcfradio mcdia 

 lit eadcm /w : i j tadem ergo quoque erit refradio 

 rubra r : i et violacea 1': i. Qiiodfi iam radii ex 

 mcdio A in medium C tranfcant , erit refradio 

 media — ;«' : i , rubra zzr' : i et violacea czv':i -^ 

 fm autem ex medio A in medium D tranfcant , 

 erit rcfradtio media —tn^: i, rubra :=;•': i et vio- 

 lacea — i?': i. Quarc in gencre fi radii ex mcdio 

 A in mcdium quodcunque N tranfeant , fueritque 

 refra^ftio media — M: i cxifientc Mn:;;;'', crit re- 

 fradlio rubra — r": i et violacea —v^: i. Cum 

 vero fit IM:=znlm idcoque «rrj-^ crit /r^xzji/r 

 =:J-^. /M, hincquc r^rrM''"^'" ct -y^rzM'^"''". 

 Qiiod fi ergo pro vnica refradionc mcdia ?n : x no- 

 ta fit refradio rubra z=:r:i ct violacca rrvri, 



tum 



