692 
(7 in 10). With these two solutions I succeeded, in establishing tor 
instance that in the leaves of Urtica dioica, the orange-yellow erystals 
dissolve more quickly than the red ones. The best results I obtained 
with phenol solutions. 
According to Wittstirrer and Mime*) xanthophyll is “spielend 
löslich” in phenol. When liquefied phenol (40 parts by weight of 
phenol in loose crystals to one part by weight of water) is added 
under the cover-slip, the orange-yellow crystals are generally seen 
to dissolve very quickly, whilst the solvent becomes orange-yellow. 
The process of solution is often preceded by a flowing together and 
the formation of orange-yellow globules and masses. Other crystals, 
generally the ved and the orange-red, the reddish-violet in the fruit 
of Solanum Lycopersicum and the orange ones which are separated 
out by Moniscn’s reagent in the flower of Dendrobium thyrsiflorum, 
dissolve much more slowly. In some preparations they are dissolved 
after some hours, in others, kept in the solvent for several days, 
erystals can still be detected. 
Because it is so difficult to mix with water phenol that has been 
liquefied by water, I have preferred for microscopic investigation a 
mixture of three parts by weight of phenol in loose crystals and one 
part by weight of glycerine. The phenomena observed are the same, 
but the mixing and dissolving proceed more quickly. With this solvent 
I have been able to show in a number of eases that the various 
crystals which had separated out, differed greatly in solubility. This 
was, for instance, the case with the flowers of Asclepias Curassavica 
and Dendrobium thyrsiflorum, as also in the leaf of Urtica dioica. 
In a few cases I experimented with a saturated aqueous phenol 
solution (solubility of phenol in water about 1 in 12'/,). With the 
orange-yellow crystals I often observed a slow deliquescence to 
orange-yellow globules which did not dissolve in the phenol solution. 
As is stated in my first paper, the microscopical observation and 
separation of the erystals of carotinoids already show that there are 
many reasons for thinking that in the vegetable kingdom several 
varieties of earotinoids occur. The results obtained with various 
reagents and solvents, sulphuric acid, zinc chloride, antimony tri- 
chloride, bromine, iodine, and phenol solutions have further confirmed 
this. In my opinion the results of microscopic and micro-chemical 
investigations have thus been brought into agreement with macro- 
chemical results. 
D RicHARD WILLSTATTER und WALTER Mree, IV. Ueber die gelben Begleiter 
des Chlorophylls, Justus Lresta’s Annalen der Chemie, 355. Bd. 1907, p. 1. 
