AN ANIMAL PIGMENT CONTAINING COPPEK. 
527 
It may be well to state here that there is no evidence, chemical or spectroscopic, 
that turacin suffers any loss of copper when treated with the somewhat diluted hydro¬ 
chloric acid used in its preparation, or even when boiled with a mixture of one volume 
of the fuming acid with one volume of water. 
§ 7. Carbon and Hydrogen in Turacin , 
The percentages of these elements, as deduced from my previously published 
analyses, were, respectively, 54'63 and 5*22. The results of combustions of the very 
carefully prepared sample of turacin with which the greater number of the analyses 
recorded in the present paper were made gave somewhat lower figures. The smaller 
proportion of carbon found may be due to the precautions taken to remove the last 
traces of fatty matter from the sample, and to decompose any oxides of nitrogen formed 
in the combustion ; the great care exercised in excluding accidental moisture may 
have reduced the percentage of hydrogen. These are the analytical numbers :— 
Combustions of Turacin. 
Substance taken. 
H 2 0 obtained. 
| 
C0 2 obtained. 
grm. 
gi-m. 
gl-LU. 
i. -1362 
•055 
•2653 
ii. '2085 
•0834 
•4076 
iii. -1435 
0611 
•2792 
These numbers correspond to the following percentages :— 
Hydrogen. 
Hydrogen corrected 
for ast. 
Carbon. 
Carbon corrected 
for asb. 
i. 4'48 
453 
53-12 
53-65 
ii. 4'44 
4-48 
53 31 
53-84 
iii. 473 
4-78 
53-06 
53-59 
The mean corrected percentages are ;— 
Carbon ... ..... 53'69 
Hydrogen s 4 . 4'60 
§ 8. Summary of Analytical Results. 
On the assumption that the only metallic constituent of turacin is copper its 
centesimal composition may be given as •—- 
