ME. A. H. CHURCH OK TURACIN, AN ANIMAL PIGMENT CONTAINING COPPER. 633 
cupric oxide. The rest of the tube was occupied by cupric oxide and 6 inches of clean 
reduced copper turnings. After clearing the apparatus of air by decomposing part of 
the sodium bicarbonate, the combination was commenced, the gases being delivered into 
a eudiometer standing over mercury, and partly occupied with a layer of caustic pot- 
ash solution. The combustion finished, the tube was swept out by decomposing the 
remainder of the bicarbonate. The eudiometer and its contents were transferred to a 
vessel of water, and the pure nitrogen gas it contained read off with the customary pre- 
cautions. 
The following results were obtained in three analyses : — 
Analysis 
Observed volume 
Volume corrected for calibre and*! 
meniscus J 
Temperature of gas . 
Barometer 
Temperature of barometer 
Water-column .... 
4 7 '6 millims. 
47 T 4 millims. 
Yin. 
53*8 millims. 
53*51 millims. 
50-2 millims. 
49-8 millims. 
7°*0 C. 
739*0 millims. 
13°*3C. 
497*9 millims. 
The observed volume of nitrogen was also corrected for the tension of aqueous vapour 
and the barometric reading for expansion of the brass scale. The usual formula of cal- 
culation was adopted, 
8°T C. 
733*75 millims. 
16°*1 C. 
495*2 millims. 
13°*0 C. 
753*6 millims. 
15°*0 C. 
495*3 millims. 
where 
?K J -lV596 -^ 
760(1 + *00366 t°) 
v represents the observed volume corrected for calibre and meniscus. 
b the height of the barometer corrected for expansion. 
b l the water-column in the eudiometer. 
b 2 the tension of aqueous vapour at f C., in millims. 
f the temperature of gas. 
v' the true volume of gas in millims. (1 millim. =*1786 cub. centim.) 
The following are the final results of the three nitrogen-determinations, vii., viii., ix. : — 
vii. viii. ix. 
Turacin taken *1445 *1665 *1604 
Turacin, corrected for ash ..... *1431 *1648 *1588 
V olume of nitrogen in cub. centims. at 0° C. "I „ „ 0 
and 760 millims. bar } 7 ' 485 8 ' 385 7 ' 864 
Weight of this nitrogen *00939 *01052 *009866 
Percentage of nitrogen 6*56 6*38 6*21 
The determinations of carbon and hydrogen in turacin were made by burning the sub- 
stance with cupric oxide containing some lead chromate, reduced copper turnings being 
placed in the anterior part of the tube. Every precaution was taken in these combus- 
