324 report — 1879. 



acetic acid, I obtained a great quantity of rhombic (nearly cubic) plates, colourless, 

 or only slightly coloured. A second experiment gave the same result. 



When palmelline obtained by the evaporation of its aqueous solution at 40° C is 

 calcined, it leaves a small quantity of ash, in which lime chlorine and iron were 

 detected. 



II. 



If, instead of drying the little plant by exposure to the air, in order to extract 

 the pahnelline, as described above, it is allowed to steep for some hours in a large 

 excess of sulphide of carbon, this liquid soon becomes a dark golden-yellow colour, 

 and on evaporation leaves, together with a little fatty matter, a large quantity of 

 xanthophyll — the yellow colouring matter of leaves in autumn — which is charac- 

 terised, as I showed in 1858, 1 by dissolving in concentrated sulphuric acid, with a 

 magnificent emerald green colour. After the complete separation of the sulphide of 

 carbon, strong alcohol extracts chlorophyll in a very pure state, forming a beautiful 

 bluish-green solution, which, on evaporation, yields nothing but chlorophyll ; and 

 this is, perhaps, the easiest mode of obtaining the substance in a state of purity. 

 When, after these two operations, the alcohol is completely separated, pure cold 

 water extracts the palmelline in the course of about twenty-four hours. 



By these successive treatments, xanthophyll, chlorophyll, and palmelline are 

 entirely separated, and the Palmella cruenta contains no more colouring matter. 



III. 



But both the treatment by water and that by alcohol, as above made known, 

 separate, at the same time as thesubatances already named, small quantities of another 

 very interesting compound, which I have isolated and have termed Characine. It is 

 the odoriferous substance which is characteristic of fresh water alga, desmids, 

 diatoms, oscillarice, &c, in general, and is highly developed in plants of the genus 

 Chara, giving to all these that peculiar marshy odour so well known to botanists. 

 This odour is due to a substance produced by the plants (a kind of camphor), and 

 not, as is generally supposed, to some products of their putrefactive decomposition. 



Characine can be extracted from the alcoholic solution, or from the water which 

 has lain over the dry Palmella omenta for thirty or forty hours. The alcoholic 

 solution is first mixed with about fifteen times its volume of water, and allowed to 

 deposit in a closed tube ; the contents of the tube are decanted from the deposit, 

 and shaken up with a certain quantity of ether. The latter is then separated and 

 evaporated. It leaves the characine in the form of a colourless greasy substance, 

 having a strong characteristic marshy odour. It is soluble in alcohol and ether, 

 almost insoluble in water, to which it communicates its odour ; its specific gravity 

 is less than that of water, on which it floats, producing those thin films which are 

 seen occasionally on stagnant water abounding in algae, and on the water of tanks 

 where alga? are cultivated. Potash does not saponify it. Abandoned to itself it 

 bither volatilises or disappears by oxidation from the surface of cold water, which 

 thus loses all marshy odour. But when heated in contact with water, in a closed 

 tube, it yields a substance melting at 83° C, very similar to ' vegetable wax,' and 

 having the odour of that substance. 



It can also be obtained from water which has stood for two days on the air- 

 dried Palmella. On the surface of the liquid, which is of a beautiful rose pink from 

 the palmelline it has dissolved, are seen numerous thin films of characine. The 

 liquid can easily be decanted off into a long narrow tube, and shaken up with ether, 

 which extracts the characine and respects the colouring matter. 



Characine is the substance to which all the fresh-water algae, oscillarise, &c, 

 owe their peculiar odour whilst in life and health. The Chara fcetida is, perhaps, 

 the plant in which it is most developed. I hope to make a more complete study of 

 it at the first opportunity. 



1 Phipson, Comptes Rendus, Paris, 1858 ; and Wurtz, Diet, de Chim. art. 'Couleur 

 des Peuilles.' 



