526 
little absolute alcohol, I ascertained, that the oily substance which 
retained the carotinoid, was dissolved and that part of the latter had 
separated more or less crystalline and gave the reactions charac- 
teristic of carotinoids. Direct treatment of the florets with absolute 
alcohol led to similar results. When the treatment with absolute 
alcohol is prolonged or when too much of it is taken, the carotinoid 
dissolves completely. 
In a few cases I succeeded in obtaining even with dilute spirit 
the separation of carotinoids in crystalline form. After being placed 
for one day in 70 °/, spirit the corolla of Calceolaria rugosa was 
seen to contain orange-yellow crystals, loose plates and aggregates. 
The petals of Chelidonium majus when soaked for a month in 
20 °/, spirit are found to contain not only orange-yellow and yellow 
drops and globules but also orange-yellow needle and thread-shaped 
erystals, some straight and some very much curved. They are often 
attached to the globules and give the impression of having grown 
out of them. In the flower of Narcissus Pseudonarcissus crystallisation 
of the carotinoid took place already after one day in 20°/, spirit. 
Long continued treatment with dilute spirit may cause the complete 
decomposition of the carotinoid; this was already the case in Narcissus 
Pseudonarcissus after a few days. 
Finally I wish to point out that on account of ARNaAuD’s ') inves- 
tigations it must be assumed that the results sometimes depend greatly 
on the season of the year. ArNnavup found, for instance, that the leaves 
of the chestnut and the stinging nettle contain most carotin during the 
flowering time (May). I also found that the separation of crystals 
in one and the same species was not always the same. This was 
especially the case in Cladophora, in which treatment with Momiscn’s 
reagent sometimes resulted in the separation of many orange-yellow 
and a few red erystals, and at other times yielded many red and 
a few orange-yellow ones. It is desirable to point out this difference. 
When these experiments are repeated by other investigators it must 
be taken into account. 
It must be admitted that the results of the above crystallisation 
experiments point strongly to the frequent occurrence of several 
distinct carotinoids in a plant. In a subsequent communication the 
behaviour of carotinoids with respect to reagents and solvents will 
be dealt with and the results of the direct and indirect methods will 
be summarised. 
1) A. Arnaup, Recherches sur la carotine; son rôle physiol. probable dans la 
feuille. Gompt. rend. CIX, 1889, 2, p. 911. 
