( 6oi ) 
Wrong, there being no Experiment of Sir Ifaac's called- 
m Queftion but what is true, and no Confequence dif- 
ferent from Sir Ifaac* s in thofe Experiments which he 
found tofucceed, but what is falfe j as may be evident 
to any one who reads Sir Ijaac Newton's Opticks with 
Attention enough to underftand them ; and has proper 
lnltruments and fufficient Dexterity and Accuracy to 
perform the Experiments. 
Our Author (tho* he profefles himfelf an Enemy to 
Hypothefes) begins his very firfl Propofition with a 
Demonuration drawn from a falfe Hypothefis ; for he 
fuppofes every Beam of Light to be as a Parallelo- 
gram of fome Breadth Jike a Ribbon, as if the Rays 
cohered together like the longitudinal Threads of the 
Ribbon • then confidering a narrow Side of the Paral- 
lelogram (which he calls the Seftion of the Beam) as an 
inflexible Line, he takes a great deal of Pains to draw a 
Confequence from it, which Experiments fhew to be falfe • 
namely, that Light paflfes with more Difficulty through 
a denfe, than through a rare Medium. He affirms, « That 
white Light never affords Colours by Reflexion.” 
That the Union of all Kind of Rays do not make 
<c white." 
“ That Light refleded from a wjoite Objecl, 
“ and feen through a dark Medium, becomes yeL 
cc low or red, , as the Medium is ffronger or weaker • 
<c that black feen through a lucid Medium appears blul 
“ or 'violet ; and green he fays is made from a 
black? Object feen Slucid , , fdark? , 
white^ flrft thro’ a ^dark, j ^ lo a JJucid^ Medium. 
“ That fome Light pafling through a refrading 
<c Medium is difperfed, which he calls more than re 
“ fratted. and fo produces Colours.” 
LIU ' In* 
