C 4087 ) 
A LattD Letter writceo to the Publiflier April 9. 1672. n ft/ 
by Ignatius Gajlon Pardies P. Prof, of the Mathema- 
ticks ia the Parifiaa Colledgc oi Clermont containing 
fome Animadverfioos upon Mr. //i4^iVw^(?;?5 Prof, of the 
Mathematicks in the Univerficy of faw^fi^^, his Theory of 
Lights printed in 80^ 
LEgi ingeniojijjim^m Mypothefin de Lumine ^ Coloribus 
ClartJfimiT^twtouu. Et quia nonnuUam Ego operam dedi 
in ijl^ contemflatione atque Experimentis peragendis ^ perjcribam ad 
Tepauca, qu£ mibi circa nova m ijlamdo&rinam occurrermt. 
Circa ipfam Luminis naturam illud profeWo exlraordinafmm vide* 
tur^ q 110 d ait vir eruditijjimm ^ Luifmi emfiare ex aggregations 
infinitorum propemodum radmum^ qui fuapte indole (uum quijqm 
colorem refer ant retineantque^ atque adeo nati apti ftnt cert a qua^ 
dam ^ pecukari ratione^ plus aiy^ alij minus ^ refringi : J^adios 
ejupnodi^ dum prmifcui tn aperto lumine canfmduntHr, nuUatemis 
difcernis fed candorem potihs referre j in refraUtom verh Jlnguhf 
unius colorif ab aliis alterius toloris fecerni^ hoc modo fecretos^ 
fub propria f3 native colore apparere : Ea carpota fub mlifuo colore^ 
V. g^^ ruhro^ videri^ apta JfntrefleBereaMttrsn/mitters radi^ 
OS folummodo rubroj, (3c. 
Ijiisc tarn extrmrdinaria Hypothefis^ qus, ipfe obfervat^ Di* 
eptricce fundamenta evertit, praxefque haSenus inftitutas inutiles 
reddit^ t&tat nititur illo Experimento Prifmatis Cryfiallini, ubi ra» 
dij per foramsn feneflrce intra obfcurum cubiculum ingreffi^ ac deinde 
iu parietem impaSij autin cbarta recepti, non in rotundum confer-^ 
mati^ ut ipfi , ad regulas refradlionum receptas attende^tij 
expecStaodum vi<!ebatur, fed in oblongam figuram extenfi apparu- 
erunt : Vnde conclujit^ oblongam ejufmodi figuram 6x eo ejp^ quod 
nonnulli radij minus y nonnuUi magis refringerentur^ 
Sed mibi quidem videtur juxta communes reeeptas Dioptrics 
leges figuramillamj non retnndamy fed oblongam ejje oportere. Cum 
tnim radij ex oppo/itis difci Solaris partibus procedentes , variam 
habeant in ipfo tranjltu Pri/matis inclinationem^ varie quoque re- 
fringi debent > ut ctm unorum inclinatio 30 faltem minutis major 
fit imlimtione aUorum , major quoque evadat illorum J^efraHio. 
X X X X J^tui 
