CHAP. VIII.] EPITHELIAL TISSUES, &c. 305 



haemoglobin ; there is, namely, a shading of the blue end of the 

 spectrum and two absorption bands between D and E ; no change 

 is, however, produced by the addition of reducing solutions. 



The author has carefully measured the positions of the bands of Turacin 

 (from Turacus persa) and he finds that the centre of the band corresponding 

 to that designated a in the spectrum of oxy-haemoglobin has a wave-length 

 of 578 ; the band in the green has a wave-length of 538 540. 



composi- The remarkable feature of this red-colouring matter 



" ura " is the constant presence of copper in it. 



Church has made many analyses of several specimens of this 

 body, and these have yielded concordant results. From these analyses 

 Church has deduced the empirical formula C w H 53 CuN 5 O i9 , which 

 demands the following percentages: 



S; 



Cu 



100-00 100-00 



The quantity of Turacin in a single bird does not exceed two or 

 three grains 1 . 



o 



SECT. 4. CERTAIN OTHER COLOURING MATTERS OCCURRING IN 

 THE ANIMAL KINGDOM. 



The study of animal colouring matters apart from those found in 

 the blood has hitherto, with few exceptions, met with but little 

 attention. While u number have been examined spectroscopically 

 with the results given below, but few have been chemically analysed 

 with anything like thoroughness 2 . - 



1 The above account is drawn from Professor Church's Memoir entitled "Researches 

 on Turacin, an animal pigment containing copper." Philosophical Transactions, 

 Vol. CLIX., Part ii. (1870), pp. 627636. 



2 The chief papers on this subject are the following: E. Ray Lankester: "Report 

 on the Spectroscopic Examination of certain Animal Substances," British Association 

 Reports, 1869. "Abstract of a Report on the Spectroscopic Examination of certain 

 Animal Substances, presented to the Brit. Assoc. at Exeter, 1869," Journ. of Anat. and 

 Phys., Nov., 1869, p. 119. "On Blue Stentorin, the colouring matter of Stentor 

 coeruleus," Quart. Journ. of Micros. Sc., April, 1873. "Preliminary notice of some 

 observations with the spectroscope on Animal Substances," Joum. of Anat. and Phys., 

 1868, p. 114. H. C. Sorby: "On the colouring matters derived from the decomposition 

 of some minute organisms," Month. Micro. Journ., Vol. vi. (1871), p. 124. "On the 

 colouring matter of some Aphides," Quart. Journ. of Micr. Sc., 1871, p. 352. "On the 

 colouring matter of Spongilla ftuviatilis," Quart. Journ. of Micros. Sc., 1871, p. 352. 

 "On the colouring matter of Bonellia viridis," ibid., p. 166. H. N. Moseley : "On 

 Actiniochrome," Quart. Journ. Micros. Sc., 1873, p. 143. "On colouring matters of 

 various animals," ibid., 1877, p. 1. This is a most important paper, giving the fullest 

 account of the Spectroscopic examination of a very large number of pigments. 



G. 20 



