94 Cc. A. MAC MUNN. 
crystallizes in rhombic plates with a metallic lustre, blue by 
reflected and orange by transmitted light. He states that 
carrotin is not an oxygen compound, but an unsaturated hydro- 
carbon, and the so-called hydrocarrotin, an impure cholesterin. 
To the pure cholesterin isolated from carrots Arnaud assigns 
the formula C,,H,,0. 
By the kindness of Dr. Schunck, F.R.S., I have had an 
opportunity of examining spectroscopically the colouring 
matter called chrysophyll by Hartsen and erythrophyll by 
Bougarel, which is identical with carrotin, according to Arnaud. 
It was crystallized in beautiful plates of a fine orange or red 
colour, by transmitted light, and under the microscope the crys- 
tals appeared reddish yellow. Dissolved in ether they formed an 
orange solution, which in deep layer transmitted the red and a 
little green, but the solution had to be diluted to a pale yellow 
colour before the bands could be seen. The first of these 
began to be shaded at A 496 and extended to \ 471, and the 
second from about A 462 to A 444. It formed a fine red 
solution in bisulphide of carbon, which in a suitable depth 
showed the following bands: first, A 535 to A 506; and, second, 
from \ 496 to \ 475. There may have been a third feeble band 
nearer violet. It was also soluble in alcohol, but not so easily 
as in the above solvents, and here it had like spectroscopic 
characters. The residue from these solutions became a fine 
blue and green with iodine in iodide of potassium, a fine dark 
blue and perhaps deep violet with sulphuric acid, and a blue 
which rapidly faded, passing into a violet tint with nitric acid ; 
so that this is certainly a genuine lipochrome.! 
As I said before, the presence of cholesterin with the lipo- 
chrome in carrots is interesting when compared with Kruken- 
berg’s observation : that some animal lipochromes are bleached 
into cholesterin-like substances. 
No animal lipochrome has yet been obtained pure enough 
for an analysis that can be depended upon; but since the 
spectroscopic and chemical characters of animal and plant 
1 Of. Dr. Schunck, “ Chemistry of Chlorophyll,” ‘Annals of Botany,’ vol. 
iii, No. 9, February, 1889. 
