45 



[Clliratill = C52 H4S O30. Bitter substance, found bj Hoehn 

 in all parts of Ophelia Cliirata. Contained in the extract, pre- 

 pared with alcohol of 60°/^. It forms a light-yellow, very hygro- 

 scopic powder of a strong and lasting bitter taste, dissolves 

 sparingly in cold, better in hot water, easily in alcohol and in 

 ether, has a neutral reaction, does not act on alkaline copper solu- 

 tion, forms a copious, white, flaky precipitate with tannic acid. 

 With acids the Ch. separates into Ophelic acid and Chiratogenin = 

 C26 H24 O G .] 



Clllorog'eillc Acid (Payen)=CAFFEic Acm. 



Clllorog'eilill. A substance contained in the root of Rubia 

 tinctorum, and distinguished by the green colour it assumes when 

 boiled with acids, but as yet not obtained in the pure state. 

 According to Kraus it appears to be identic with Rochleder's 

 Rubichloric acid and with Runge's E-ubiaceic acid. Remains, be- 

 sides sugar and minei"al substances, in the liquid obtained for the 

 preparation of Rubian, after the precipitate produced by acids 

 has been filtered ofi". Precipitate the aqueous decoction of madder 

 with oxalic acid, filter and neutralise the liquid -with chalk, 

 filter again and evaporate the liquid on the water-bath until a 

 dark-brown thick syrup is obtained. The latter dissolves in water 

 and leaves behind brown products of decomposition originated in 

 the course of the evaporation (while the solution has an acid re- 

 action on account of phosphoric acid, and assumes a green colour 

 when boiled with acids). Precipitate the solution with subacetate 

 of lead, remove the excess of lead in the filtered liquid by sul- 

 phuret of hydrogen, filter again and evaporate over sulphuric 

 acid ; a brownish-yellow, honey-like substance is obtained, which 

 does not dry up again. This is Chlorogenin, mixed with a little 

 sugar, which exists readily formed in the madder, and with the 

 acetates of potash, lime and magnesia. It has a nauseous, 

 sweetish and bitter taste, throws down a brown jjowder when 

 evaporated in the aqueous solution, dissolves in alcohol, not in 

 ether; emits an offensive smell when boiled with diluted hydro- 

 chloric or sulphuric acid, becomes dark -green and throws down a 

 dark-green powder. 



Cllloropliyll is according to Fremy a mixture of a yellow and 

 a blue pigment. By shaking an alcoholic tinctiire of chlorophyll 

 with a mixture of two parts of ether and one part of moderately 

 diluted hydrochloric acid, the ether dissolves the yellow matter, 

 while the acid beneath assumes a beautiful blue colour. By 

 mixing the two liqviids by means of alcohol the green colour is 

 restored. The yellow pigment, isolated in the above manner, is 

 called by Premy Phylloxanthin, the blue Phyllocyanin. Closer 

 investigations of these two comjiounds are wanting. 



