Sllf ARTlItUt II. CUURCU OX TURACIX, 641 



the six genera of MusopbagidEe three contain the crimson jiigment 

 which 1 named turacin. These are: — Musoplicuja, 2 ; Taracus, 

 21; Gallh'ex, 3 ; or 26 turacin-bearers in alL The three remain- 

 ing goneia from, which turacin is absent are : — Cori/ihceola, 1 ; 

 C/dzcerhis, 4 ; and G>jinnoschizorhis, 2 ; or 7 in alh There are 

 two remarks that may be interposed in this connection. The first 

 is that the crimson pigment is identical in all the species, and 

 occurs not onl}^ in from 6 to 18 of the primary and secondary 

 pinion-feathers, but also in all other similarly-coloured feathers 

 or parts of feathei'S which are found on some of these birds- — for 

 example, in the head-feathers of Musojyhaga violacea, in the ci-est- 

 feathers of TuracihS donaldsoni, T. Jischeri, and T. meriani, and 

 ill the head-feathers of Gcdlirex johnstoni behind the crest. The 

 second remark refers to the pinion-feathei-s of three out of four 

 species of ChizcerJiis, which have white patches bare of any pig- 

 ment pretty much in the same position as the crimson patches m 

 the turacin-bearers, although mostly confined to one side of each 

 shaft — a curious coincidence, at all events. 



I mny now turn to the properties of turacin. We have already 

 seen that it is soluble in wa,ter. Not, we ma}^ add, in hard water, 

 but in clean rain water or, better, in distilled w^ater. It is still 

 more easily dissolved by weak alkaline liquids, extremely dilute 

 ammonia being the best solvent. From this crimson solution, the 

 colouring-matter, the turacin, is precipitated as gelatinous flocks 

 on neutralization by hydrochloric or other acid. The flocks that 

 separate when collected and dried form a deep red amorphous 

 mass, crimson by transmitted light when in thin layers, but 

 exhibiting a surface-lustre of a purplish hue, not unlike that 

 reflected from crystals of potassium permanganate. Thus the 

 appeai'ance of solid turacin cannot be said to be accurately de- 

 scribed when it is spoken of as " a metallic red oi* blue powder,"' as 

 in the Enc. Brit. 11th ed. vol. x. p 226 a. Turacin is insoluble 

 in alcohol, ether, chloroform, petroleum-spirit, Ijenzol, and the 

 usual solvents of resins and oils. In order to obtain it in a pure 

 state special procedure is required to prevent its contamination 

 Avith the natviral oil of the feathers, while it is not possible to free 

 it completely from all traces of non-essential mineral matter. 

 The action of lieat on dry tuiacin presents seveial points of 

 interest. It sufl^ers no change at a temperature rather above that 

 of boiling- water, but at or near the boiling-point of mercury it is 

 profoundly modified without loss of weight and becomes insoluble 

 in alkaline liquids. If this altered tui'acin be now exposed to a 

 higli tempei'ature in the presence of air its combustible con- 

 stituents burn away,lea.ving a black ash, amounting in the purest 

 samples to about 9'8 per cent, of the original weight. This ash 

 consists almost entirely of oxide of copper, the amount corre- 

 sponding to at least 7 per cent, of that metal in the tiu-acin itself. 

 Here again the statement in the Enc. Brit. {loc. cit.) needs correc- 

 tion, for this is a fixed percentage, not one that varies from " 5 to 

 8." In furtlier describing the action of heat upon dry turacin it 



