CONVERSAZIONE. 
681 
The Chairman having announced, amidst great applause, that Dr. Attfield 
had just authorized him to say that he should be happy to present his set of 
metrical weights and measures to the Museum of the Society, the meeting ad¬ 
journed. 
CONYERSAZIONE. 
The Annual Conversazione, which was held in the Society’s rooms on 
Tuesday, the 18th of May, was attended by an unusually large number of 
visitors who had responded to the invitations issued by the President and 
Council, and abundant material for discussion was afforded by the display 
of objects illustrative of the most recent discoveries in pure and applied 
sciences which each apartment contained. 
Through the kindness of Professor Church, M.A., those present had an 
opportunity of seeing specimens of turacine, a new pigment, concerning which 
the discoverer has communicated to us the following memoranda:—“ Turacine 
is a pigment contained in the red feathers of certain birds belonging to the 
Musaphlagidce. It has been extracted from several species of these birds, of 
the genera Corytliaix and Musaphlaga. Weak caustic soda is employed 
to dissolve the turacine from the red barbsthe dissolved pigment is then 
precipitated by hydrochloric acid, washed and dried. Thus prepared, tura¬ 
cine appears in the form of dark scales having a red-violet lustre. Its spec¬ 
trum resembles that of scarlet emorine,. having two absorption bands in the 
green. The most remarkable characteristic of turacine is, however, the 
occurrence in it of a definite, constant, and irremovable proportion of the 
metal copper. The ash of turacine is pure black copper oxide. Copper 
occurs only in the red parts of the feathers, not in the black A few red 
barbs burnt, and moistened with hydrochloric acid, give the copper spectrum 
at once in the Bunsen flame. The birds, when bred in England and kept in 
captivity, produce the same cupreous pigment. The plantain fruits on which 
some of the species chiefly feed have been found to contain distinct traces of 
copper. It should be added that it has been conclusively proved that the 
copper is constant in amount in the turacine derived from different species, 
and that it cannot arise from any accidental source whatever. The atomic 
relations of turacine are nearly given in the formula C 5( ,JE 56 CuiN 5 0 19 . It 
contains 59 per cent, of copper.” The specimens exhibited comprised,— 
turacine; turacine dissolved in soda; turacine suspended in water; wings 
and feathers of the Corythaix albocristata, one of the commonest touracos, 
or plantain-eaters ; a feather touched with soda solution in three spots, 
and washed. The spectrum of this remarkable body was shown by Air. 
Browning. 
Much interest was manifested in an experiment shown by Mr. Roberts, 
illustrating Mr. G-rakam’s discovery of the expansion of palladium by hy- 
drogenium. A slip of palladium foil, one side of which has been varnished, 
is made the negative electrode of a voltameter. On passing the current the 
hydrogen, or much of it, instead of being evolved, is absorbed on one surface 
of the palladium, which, being expanded, becomes curled like a watch-spring. 
On reversing the current the effect is reversed, as the evolved oxygen then 
carries off the hydrogen. 
The spectrum of a supposed new element jargonium, contained in jargon, 
vi 7 as exhibited by Mr. Browning (Mr. H. C. Sorby, F.R.S., the discoverer, 
having kindly lent the jargon for the purpose): some new and very beautiful 
lakes produced from coal-tar colours were contributed by Mr. W. F. Perkin, 
vol. x. 3 A 
