Study of Spirogyra nitida. - 1 1 



stances were incorporated with the chlorophyll. linked, 

 the presence of a resinous substance in a plant of this 

 character is hardly to be expected. Yet if we consider the 

 close relationship between the tannins and the resins some 

 light is thrown upon the matter. The tannin content of 

 the cell is comparatively great— S.71 percent— and accord- 

 ing to Bastian * and others, resin is, in some plants at least, 

 produced from tannin. 



The residue from the petroleum ether extraction was 

 treated with ethyl ether until everything soluble in this 

 menstruum had been removed. The extract was evapor- 

 ated to dryness in a tared flask and weighed. The dry 

 material so prepared was treated with cold water, btit 

 nothing dissolved. It was then taken up with absolute 

 alcohol and proved to be totally soluble in this solvent. 

 The solution was clear, dark green, and seemed to consist 

 of very pure chlorophyll. The quantity amounted to 2.62 



per cent. 



An extraction of the dry residue with absolute alcohol 

 gave a tannin content of 8.71 per cent. The method used 

 was that of Lowenthal, as modified by Procter,! in which 

 the tannin solution to be determined is titrated with a per- 

 manoanate solution of known strength, after the addition 

 of an indigo carmine solution. 



The aqueous extraction yielded 14.70 per cent, of a gum 

 soluble in water, but insoluble in dilute alcohol. The addi- 

 tion of strong alcohol to the filtrate produced a precipitate 

 of dextrine-like carbohydrate, which amounted to 7.24 

 per cent. This high content of mucilaginous substance is 

 perfectlv accounted for by the appearance of the plant and 

 by its soft mucilaginous character. 



The acid content was found by precipitating a portion of 

 the aqueous extract with lead acetate, weighing the precip- 

 itate on a tared filter, then igniting. The loss in weight 

 represented the organic acids and amounted to 3.01 per cent. 



* Am. Jour. Pharm., Vol. 68, p. 137. 



f Jouru. Soc. Chem. Industry, Vol. 3, p. 82. 



