46 



[According to tlie researclies made by Kraus, Sorby and others 

 on the green colouring matters of leaves, spectrum analysis has 

 revealed the existence of at least ten different colouring substances 

 more or less separable by means of sulphide of carbon, alcohol 

 and water, used in varying combinations. Amongst these substances 

 are a blue-green and a yellow-green, called respectively blue 

 and yellow chlorophyll, and five yellow substances : orange xantho- 

 phyll, xanthophyll, yellow xanthophyll, orange lichnoxanthin and 

 lichnoxanthin. As these colouring matters ai-e rapidly decomposed 

 by acids, Fremy's blue and yellow Chlorophylls are but products 

 of decomposition. Of the above colouring matters, orange xan- 

 thophyll occurs in considerable quantity in Oscillatorise, blue chlo- 

 rophyll in olive Algse, xanthophyll in Porphyra vulgaris (Algae), 

 yellow xanthophyll in various pale-yellow flowers as Chrysanthe- 

 mums, &c., and lichnoxanthin in Clavaria fuciformis. Xanthophyll 

 and yellow xanthophyll give absorption-bands, not lichnoxanthin. 

 On addition of a little hydrochloric acid to the alcoholic solutions, 

 the first and the third of the three last-named matters fade slowly 

 without altering theii* colour, while the second is changed into 

 another yellow substance with two absorption-bands and then into 

 deep blue. These three yellow substances are all soluble in sul- 

 phide of carbon, they exist in green leaves and also generally in 

 yellow flowers though mixed in different proportions.] 



[Solutions of Chlorophyll are decomposed by small quantities of 

 hydrochloric acid, and yield on filtration a solid black residue and 

 a yellowish- brown liquid. The latter, on addition of more hydro- 

 chloric acid, assumes a deep-green colour and yields by filtration a 

 yellow residue and a pure blue liquid. The above black matter 

 shows, according to Filhol, a crystalline structure of radiated 

 needles under the microscope in the case of Monocotyledons, but 

 is amorphous with Dicotyledons. It dissolves very sparmgly in 

 cold alcohol of 85%, abundantly on boiling, also in ether and ben- 

 zol with yellowish-brown, in sulphide of carbon with yellow, in 

 chloroform Avith violet, and in acetic acid with blue- violet colour. 

 Concentrated hydrochloric and sulphuric acids dissolve it slowly 

 with green colour, probably under decomposition. The solvition 

 of the crystalline black matter in acetic acid assumes a splendid 

 green colour when mixed with traces of the acetates of copper or zinc 

 and heated to boiling.] 



Cll0lestearill = Ci8 H24 0-f HO. Exists, according to recent 

 investigations, also in the vegetable kingdom and especially in the 

 seeds and young parts of various plants (in malt, &c.) From peas 

 it is obtained in the following mannei-. Digest with warm alcohol 

 of 94°/^, evaporate to honey-consistence, dissolve in water, add 

 oxyd of lead, boil until clear, allow to cool, throw away the water, 

 treat again with hot alcohol, remove the lead in the tinctui-es by 



