DR. BREWSTER ON REFLECTED LIGHT. ' 199 



Image at the 

 Names of Oils. Image at the Surface of Prism A. Surface of Prism B. 



Oa of Bergamot . . (Three very fine orders. First limit at 73°. Heat spoils! yellowish white. 

 ° I hrst order. J 



oa of Beech Nut ^^'tt ^''u"'"' '''f"?' ^"'^/'" '^'^°''^- ^'''^ ^™" ^^] Yellowish white. 

 [ 73 . Heat spous hrst order. J 



c ^- n■^ f Two tolerable orders. First red and blue bad, second red 1 v- ii ..•„i, „!,% 



Spermaceti Oil.... I ,„a blue good. First limit at 73°. | Yellowish white. 



Oil of Olives Three good orders. First limit at 73°. Whitish yellow. 



Grass Oil Three good orders. First limit at 73°. Grayish white. 



Oil of Rosemary . . Two good orders and more. First limit at 73°. Whitish yellow. 



oa of Poppy .•.•{'^^the%'olou"r*'''^"'' ^''''^'^'^'^^°- "'^' '"J"'"' } YeUowish white. 



oa of Lavender . . T^":^ S^°\'''^f'; ^'''' '^^ ^""^ ^''' ^^"^ "^'^ «"^- j Yellowish white. 

 \ h irst limit at 74°. J 



oa of Camomae ,.< Two good periods. First limit about 60°. > °,- •' 



oa of Wormwood .{'^\'^^^f°°^ P^"°*^^- ^^^^ "™'* ^* ^^°' '^"^ "°* ^^" } Yellowish white. 



Bhela Juice ( ^'"'^f .^'"v.' ^^^e'-^.^Vr ''=™Pf/o*"'^^«' b"* ^"^'y brought 1 yellowish white. 



(_ out by heat. First bmit at 73°. J 



Muriatic Acid .... Traces of tints. Yellowish white. 



Sulphuric Acid ... . Two pretty good orders. Yellowish white. 



Vitreous Humour of! m r ^ t> • i ^ 



the Haddock . . . . / ^'^^'^^^ "^ '=°^°"'''- ^"S*^*' 



Oil of Rhue No colours. Bright. 



Oil of Boxwood . . No colours. Bright. 



Alcohol Traces of reddish, bluish, and greenish yellow tints. Bright. 



Water Traces of tints. Bright. 



The experiments * recorded in the preceding pages may be divided into two 

 classes. 



I. Those which establish the existence of reflecting forces at the confines of 

 media of the same refractive power ; and, 



* These experiments have been extended to a great number of mixed oas and to soft solids, gums 

 and resins, combined with the prisms A and B. 1 have also substituted for these prisms others of 

 different kinds of glass, which give similar results ; and I have examined the phsenomena at the con- 

 fines of different fluids an^ a great number of minerals of various refractive powers between chromate 

 of lead and fluor spar. 



