t 
refractive and dispersive Powers. 371 
Anime 
1,535 
Radcliffe crown glass - 
T533 
Pitch 
— 
Centre of crystalline of 
fish, and dry crystal- 
line of an ox 
L53° 
Canada balsam 
1,528 
Crown glass , common 
L525 
Selenite 
L525 
Caoutchouc 
1,524 
Gum lac 
. — 
Dutch plate glass 
1.517 
Human cuticle 
— 
Gum arabic 
1,514 
Balsam of capivi 
1,507 
Oil of amber 
1,505 
English plate glass 
1,504 
French plate glass 
1,500 
Oil of nutmeg 
i,497 
Sulphate of potash - 
i,495 
Tallow, cold 
i,49 
Iceland spar, weakest 
1,488 
Camphor 
1,487 
Linseed oil 
i, 4 8 5 
Butter, cold 
1,480 
Essence of lemon 
1,476 
Oil of turpentine, com- 
mon - - 1,476 
rectified 1,470 
Oil of almonds — 
• olives - - 1,469 
peppermint - 1,468 
lavender - 1,467 
Tallow, melted - 1,460 
Alum - - - 1 ,457 
Spermaceti, melted - 1,446 
Crystalline lens of an ox 1,447 
to - 1,380 
Computed average of 
ditto - - 1,430 
Sulphuric acid - 1,435 
Fluor spar - - 1,433 
Nitric acid (sp. gr. 1 ,48) 1,410 
Alcohol - - 1,37 
White of an egg - 1,36 
/Ether - - 1,358 
Vitreous humour of an 
eye - - 1,336 
Water - - 1,336 
Atmospheric air 
(Hauksbee) - 1,00032 
« 
