98 ESSAYS ann OBSERVATIONS 
to reconcile all phexomena with the new 
principles difcovered by Sir Ifaac New- 
ton: And when they find, to their mor- 
tification, that’ this will not always fuc- 
ceed; phenomena muft be difguifed and 
nature tortured, to hide their ignorance. 
From the lazy method of philofophizing 
in the clofet, among books and diagrams, 
there never arofe, there never will arife, 
any difcovery of confequence: Great in- 
ventors ufually underftand the extent of 
their own principles too well, to leave 
much of the application of them to o+ 
thers. 
THE -difcovery of the different refran- 
gibility of the rays, was an ineftimable 
addition to natural knowledge ; as it 
ferves, at once, for explaining innumera- 
ble phacnomena ia nature which flow from 
‘it as immediate and neceflary confequen- 
ces: And, if it {hall be demonftrated by 
the obfervation propofed in N° 49. that 
the differently-coloured rays really move 
with different velocities, our theory of 
light will be ftill farther improved ; asthe 
diffe= 
