634 MR. A. H. CHURCH ON TURACIN, AN ANIMAL PIGMENT CONTAINING COPPER. 
tions to ensure trustworthy results, especially as, on account of its rarity and costliness, 
the amount of material burnt was necessarily small. 
Analysis 
X. 
xi. 
xii. 
xiii. 
Turacin taken .... 
•1040 
•1400 
•0835 
•1937 
Turacin, corrected for ash . 
•1030 
•1385 
•0825 
•1916 
C 0 2 obtained 
•2065 
•2780 
•1635 
•3828 
H 2 0 obtained .... 
— 
•0670 
•0390 
•0870 
Percentage of carbon . 
54-66 
54-75 
54-06 
54-49 
Percentage of hydrogen . 
— 
5-38 
5-21 
5-06 
I have gathered into the following Table the percentage results deduced from the 
analyses above given : — 
Carbon. 
Hydrogen. 
Copper. 
Nitrogen. 
54 '66 
5-75 
6-56 
54-75 
5-38 
5-89 
6-38 
54-06 
5-21 
6-03 
6-21 
54-49 
5-06 
5-91 
54-49 
5-22 
5-90 
6-38 
If, however, we exclude the low percentage of carbon (54-06) obtained in one case 
where the amount of substance taken was insufficient to secure an accurate result, we 
may deduce the following mean percentages as representing the centesimal composition 
of turacin dried at 100° C. : — 
Carbon . . . 
. . . 54-63 
Hydrogen . . . 
. . . 5-22 
Copper . . 
... 5-90 
Nitrogen . . . 
. . . 6-38 
Oxygen (diffi) . . 
. . . 27-87 
100-00 
If we assume that one molecule of turacin contains one atom of copper, we are led 
to conclude that the relations between its constituents may possibly be represented by 
the empirical formula 
C50 H56 Cu N 5 0 19 , 
which demands the following percentages: — 
Theory. Experiment. 
(Mean.) 
C 50 = 
600-0 
54-87 
54-63 
H 56 = 
56-0 
5-12 
5-22 
Cu = 
63-5 
5-81 
5-90 
N 5 = 
70-0 
6-39 
6-38 
Ol9 = 
304-0 
27-81 
27-87 
1093-5 
100-00 
100-00 
