518 
the formation of red or reddish yellow erystals, especially in the 
stomata. Morrscn *) repeated the experiment with the leaves of 
Elodea and also observed such crystals which according to him, 
correspond to the crystals he obtained by his potash method. Tames”) 
experimented on a great number of plants and various parts of 
plants with dilute acids, as, for example, hydrochloric acid, oxalic 
acid, tartaric acid, chromic acid, pieric acid, acetic acid, and hydro- 
fluoric acid. Pierie acid was used in a solution of alcohol, the other 
acids in aqueous solutions of various strengths. The investigation 
yielded positive results in the case of leaves, and other green parts 
of plants, flowers, green algae and Fucoideae. In all the cases inves- 
tigated, over 30, crystals were obtained after some hours or days 
which, according to the above-mentioned writer, agreed completely 
with the erystals which had been obtained by the potash method 
and were found to consist of carotin. With yellow variegated, yellow 
autumn and etiolated leaves the experiment was without result, a 
fact which Tammes*) is unable to explain. 
When plants or parts of plants which contain chlorophyll are 
investigated with dilute acids allowance must be made for the action 
of the acids on the chlorophyll. When Moniscn’s reagent is used the 
chlorophyll dissolves with saponitication of the ester, separation of 
phytol and formation of chlorophyllin potassium *), but the action of 
acids on the chlorophyll produces insoluble derivatives. WiL1sTATTER, 
who treated alcoholic extracts obtained in the cold from dried plants 
with acids, obtained, when the magnesium had been eliminated, 
phaeophytin °), which like chlorophyll *) consists of two component 
parts, namely, phaeophytin a (phytylphaeophorbide a) and phaeo- 
phytine b (phytylphaeophorbide b). Earlier investigators also already 
dze. p. 26. 
2) 1. c. p. 216 et seq. and p. 242 et seq. 
8) I. e. p. 220. 
t) Richard Whitustartrer, (Untersuchungen über Chlorophyll), IL. Zur Kenntnis 
der Zusammensetzung des Chlorophylls, Justus Liebig’s Annalen der Chemie, 350. 
Bd. 1906, p. 48. 
Ricuarp Witisratrer und Frrpinanp Hocueper, III. Uber die Einwirkung von 
Säuren und Alkalien auf Chlorophyll, 1. c. Bd. 354, 1907, p. 205. 
5) R. Wiuusrarrer, IW. Zur Kenntnis der Zusammensetzung des Chlorophylls, lc. 
R. Wursrärrer und F. Hocueper, |. c. 
Bicgarp Wiuustdrrer und Max Ister, XX. Uber die zwei Komponenten des 
Chlorophylls, 1. c. Bd 390, Heft 3, 1912, p. 269. 
6) Ricuarp Wuustirrer und Max Urzineer, XVI. Uber die ersten Umwandlun- 
gen des Chlorophylls, 1. c. 382. Bd. p. 129. 
R. Witsriirrer und M. Iszer, 1. c. 
