516 
PROFESSOR A. H, CHURCH ON TURACIN, 
With regard to the formation of turacin in the organism of these birds we have 
much to learn. That the pigment is not always present in the blood is certain. I 
could not detect a trace of it in a specimen of Turacus persa , which was examined 
immediately after death, although I did recognise the presence of a minute quantity 
of copper in the ash of its flesh. It is desirable that the blood of the birds should 
be tested for turacin during the moulting period. 
§ 3. Isolation of Turacin. 
The mode of extracting turacin from Touraco feathers has been slightly improved. 
The red parts of the vane are first thoroughly washed with distilled water, and then, 
after drying, treated successively with absolute alcohol and with ether. The material 
is allowed to dry before being extracted, not, as previously, with very dilute sodium 
hydrate solution, but with exceedingly weak aqueous ammonia. The crimson solution 
thus obtained is filtered, and then precipitated by pouring it into a large excess of 
pure strong hydrochloric acid diluted with twice its bulk of water. It is curious to 
observe the immense bulk assumed by freshly-precipitated turacin. Thus, in an 
operation in which about 4 grms. of this pigment were dealt with, it was necessary to 
increase the volume of the mixture of turacin, hydrochloric acid, and water to nearly 
one gallon before its thick consistency could be so reduced as to permit of its being 
brought upon the filter. Filters of the finest calico were found to be far preferable to 
those of paper; they were first thoroughly cleansed by means of boiling distilled 
water: the method of vacuum filtration was adopted. All the operations should be 
conducted quickly; exposure of the moist turacin to light should be avoided as far as 
possible. 
§ 4. Characters of Turacin. 
The account given in my previous paper of the properties of turacin and of its 
behaviour with several reagents needs one addition. When powdered turacin is 
dissolved in cold oil of vitriol* it is profoundly changed, a part of its copper being 
removed and a new colouring matter produced. On pouring the sulphuric acid solu¬ 
tion into a considerable volume of water, a flocculent precipitate of a reddish-chocolate 
colour appears. Collected on a filter and thoroughly washed with hot water, this 
precipitate is found to be still rich in copper, although a part of the metal has been 
withdrawn by the action of the sulphuric acid, and is found in the filtrate. The 
precipitate dissolves in dilute ammonia-water, with a crimson hue.t Dr. C. A. 
MacMunn, of Wolverhampton, lias kindly examined this solution for me, and states 
* Oil of vitriol (containing 96 per cent, of H 2 S0 4 ) appeal’s to exert the same action on turacin, and to 
yield the same derivative, at temperatures much higher than 14° C., at -which the first experiment was 
tried. 
f [The ammoniacal solution of this substance, which I have called turacoporphyrin, exhibits a bright 
red fluorescence which is not seen in a similar solution of turacin ; the solution in dilute sulphuric acid 
also fluoresces red.—Postscript, September 1, 1892.] 
