PLATE L. 



Fig. 321. 



Red end. 



Pine end 



A. Indefinite spectrum of 

 many pink colours. 



B. Logwood, with bicar- 

 bonate of ammonia. 



C. Brazil wood, with bicar- 

 bonate of ammonia. 



D Fresh ijlocd. 



E Alkanet root in alum. 



F. Deoxidized' hseraatin 

 from blood stain two 

 years old. 



Mr. Sorby'a spectrum eye-piece for the 

 microscope, with arrangement for pro- 

 ducing two spectra for comparison 



p. 219 



Absorption bauds produced by different 

 substances, p 2J1 



Arrangement for altering the leu^th an<l 

 breadth of the spectrum, p. '^19. 



012 3 



ABC D 



E b 



1 . .?03. 



i ' ' i i . i !' _; 



Cell for examining solutions by th spectrum 

 microscope. Half the real size, p '.23. 



Fief. 324. 



Scale for measuring the exact position of the absorption bands, 



p. '2'35 



w 



Y-^i 



Tube to fit over object glass to 



prevent reflection of extraneous 



light, p. -220. 



Fig. 525. 



Wedge-shaped cell, for examining solutions in the 

 spectrum microscope, p 2^3. 



Glass tube for containing solutions for examination 

 under the spectrum microscope. Half the real si7.e. 



p. 223. 



[To face page 224. 



