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XXL Researches on Turacin, an Animal Pigment containing Copper. By A. H. Church, 
M.A. Oxon., Professor of Chemistry in the Royal Agricultural College , Cirencester. 
Communicated by JDr. W. A. Miller, Treas. and V.P.R.S. 
4 Received May 4, — Read May 27, 1869. 
Origin of the present Inquiry. — The stability of the colours which the feathers of birds 
display has been repeatedly proved. These colours are due either to what we may call 
the optical character of the surfaces of the web, or to the presence in it of definite 
colouring-matters. These pigments may be opaque like enamel, or translucent and per- 
meating the substance of the barbs ; they have been as yet but very imperfectly studied. 
In a few instances only have they been actually separated from the structures containing 
them, while in no case have they been completely examined from a chemical point of 
view. So far as I can learn, we have no exact information as to the amount and the 
deportment, chemical constitution and reactions of those substances which M. Bogda- 
now*, some twelve years ago, succeeded in extracting from the feathers of many birds, 
and notably from the red feathers of Calurus auriceps and Catinga ccerulea. Before 
giving an outline of my own experiments in this direction, I will mention the particular 
circumstances which led to the prosecution of the present research. 
A few years ago Mr. W. B. Tegetmeier pointed out to me a singular property of the 
red feathers of the bird called the Touracou, or Plantain-eater. These feathers yield 
up a part of their colouring-matter to pure water, a beautiful rose-coloured solution 
being thus obtained. Mr. Tegetmeier’s attention had been drawn to this fact, and he 
at once perceived that it was worthy of fuller investigation than it had already received. 
On further inquiry, I find that Mr. Ward of Wigmore Street had noticed the evan- 
escence and solubility of the red tint in question many years ago, and that other ob- 
servers, within the last few years, have even succeeded in staining pieces of paper with 
the red solution which these feathers yield. In order that it may be seen what was the 
position of the inquiry when I commenced in 1866 my experiments on this subject, I may 
cite the authority of some private letters which have been placed at my disposal through 
the courtesy of Mr. Hugh Owen. These letters were written by Dr. Benjamin Hinde, 
principal Medical Officer on the Military Staff at Bathurst, on the Gambia. In one of 
his letters, dated May 1865, Dr. Hinde enclosed a piece of paper stained with the red 
pigment of 1 inch of a feather of the violet Plantain-eater, Musophaga violacea. He 
says that the moment soap touches the feathers the colour runs, but that it is difficult 
of extraction with pure water. But he adds, “ the birds I sent home washed themselves 
* Comp. Rend. xlv. p. 688 ; xlvi. p. 780. 
