DR. BREWSTER ON REFLECTED LIGHT, 197 



Image at the 

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



Canada Balsam /Above two orders of colours; pink of second the best. Im-1 Grayish or bluish 

 ' ■ \ proved by heat. / white. 



Oil of Tobacco .. Two faint orders of colours. Heat brings out nearly three. Grayish white. 



n-i „<• ri^ /Two faint orders. Heat brings out part of a third. Firstl Yellowish white 



Oil of Cloves .... I jj^^ ^^ pj^j^ ^^ j^j^^ ^^^^ » g^o „^f incidence, J ^h £ ^'^^ 



Oil of Sassafras , . Two orders. First red pale. First blue good. Grayish white. 



Balsam of Capivi . . See page 191. 



Muriateof Antimony Two tolerably distinct orders of colours. Grayish white. 



r Faint grayish, be- 



Oil of Cummin J "^^^ beautiful orders. A fine yellow in the second order. J coming more in- 



Heat spoils them all. *> tense and yellow 



L by heat. 



("Two faint orders, the second red and second blue being"] 

 vr,,. r»;i J tolerably good. Heat brines out two fine orders, the ( v n • i i • 



^"* °^ ] first limit of pink and blue ending at about 76° of inci- ^ Yellowish white. 



L dence. J 



Oil of Pimento. . /Three good orders of colours. First limit of pink and") Pale blue, very faint 

 ' ■ ■ ' \ blue at 65° of incidence. J at great incidences. 



Oil of Sweet Fennel- 1 rp , • i j ' 1 ,^, . , 



see^g I Two orders ; pmk good. | Bluish gray. 



Wood Oil . . . . / ^^""^^ 8°**^ orders of colours. First pink and blue fine. 1 Bluish gray, weaker 

 I First limit of pink and blue ends at 65°. J at great incidences. 



Oil of Amber . / ^'^° excellent orders of colours. First limit of pink and 1 Pale blue, very faint 

 •••• \ blue at 65°. Improved by heat. / at great incidences. 



Oil of Rhodium . . {^]:,:fthem'''^°"* ^""^"' ^'''* ^' '' ''°- "''' '""} Yellowish white. 



rAt temp. 50° three orders, which are not good, especially") 

 Treacle < the pink of first and blue of second order. Heat brings ^Yellowish white 



out three splendid orders with periods, as in castor oil*. J 



Balsam of Sulphur .(^h^je Sne orders. First limit of pink and blue at about rFig-y;^^;^^ 

 L L at great incidences. 



Honey | Two pretty good orders. First limit at about 65°. | ^^'^^^ yellowish 



Oil of Angelica • • {^7ondtd good"'^''''" ^irst pink and first blue fine ; se- J ^^j^;^^ ^^y^^ 

 Oil of Nutmeg Three not very bright orders. First limit at 73°. Whitish yellow. 



* The treacle used in this experiment is much inferior in refractive power to the prism A. 



