Fic. 4. 
Fia. 5. 
132 Progress in Science. (January, 
twentieth band, lines of which are said to be y3,,th of a Paris line apart. 
These new bands have not at present been resolved. 
Mr. J. J. Monteiro, ina letter to the “‘ Chemical News,”* gives some account 
of the habits of the ‘plantain eaters” (Turacus albo-cristatus), the birds 
from the feathers of which the colouring matter turacin was extracted by 
Professor Church, and which is distinguished by its remarkable two-banded 
spectrum. These birds are common on the West Coast of Africa, and in the 
part known to the writer, viz., from Loango, in 5° S. lat., to Fish Bay, in 15° 
S. lat., they abound. Over the whole country mentioned, and for a consi- 
derable distance inland, copper is found, most abundantly distributed, as mala- 
chite or green carbonate; specks of the green mineral are everywhere to be 
found. Mr. Monteiro considers it highly probable that the birds swallow 
small particles of the cupreous substance with the gravel, &c., so commonly 
taken by all birds. This may account for the large quantity of copper disco- 
vered by Professor Church in the feathers of these birds. Mr. Sidney Lupton 
also remarks+ that two green love birds (Melopsittacus undulatus) were in the 
habit of pecking at the bars of their cage or any brass-work accessible to them. 
The feathers of these birds also yielded traces of copper. The spectrum of 
the green feathers had not been examined. The lower band of the turacin 
spectrum (Fig. 5) corresponds in position, although not in extent, with the band 
of ruby glass (Fig. 4): extent of absorption, however, is in many cases de- 
IRE 
pendent upon the intensity of the coloured medium, many bands, as those of 
the aniline dyes, being easily made to absorb to a greater or less extent, ac- 
cording to the amount of dilution or the thickness of coloured medium through 
which the light is allowed to pass. (The bands between the Frauenhofer 
lines, extending half-way across the upper spectrum, are those of nitrate of 
didymium, and, from their sharpness and convenient distribution, are conye- 
nient in mapping spedtra by artificial light). 
ELectricity.—Mr. Casselberry, of St. Louis, has been experimenting for 
several years with voltameters. He finds as the result that two voltametric 
apparatus (of the ordinary kind) connected together, not in series, but with 
their oxygen and hydrogen eletrodes attached by wires, the oxygen electrodes 
to the positive, and the hydrogen electrodes to the negative pole of a battery, 
that there is then generated in each voltameter an equal quantity of gas to 
that generated in only one voltameter with the same battery. The experi- 
ment is borne out by the law of derived circuits, the second yoltameter being 
* “ Chemical News,” vol. xxviii., p. 201. 
+ Ibid, vol. xxviii., p. 212. 
—————F 
