CHLOROPHYLL. 113 



mixture of 1 volume of 98 per cent, spirit to 5 of ether, the resin 

 compound alone passes into solution. 



Gladding's method depends upon the insolubility of the silver 

 salts of fat acids in ether, in which resinate of silver dissolves 

 both easily and abundantly. For working details of the process 

 reference must be made to the original paper. 



If oleic acid is present, the separation by a and b will be inac- 

 curate, as the resin will be contaminated with oleic acid. These 

 methods might, however, be employed to separate oleic from 

 stearic and palmitic acid in absence of resin. If only a small 

 quantity of oleic acid is present, the resin may be estimated by c. 

 On decomposing the lime salt with an acid, a little oleic acid 

 may be precipitated with the resin, but the former remains sus- 

 pended in the liquid, whilst the latter agglutinates into lumps. 

 After separating the resin, the oleic acid may be removed by 

 shaking the liquid with ether. 



The estimation of resin in the presence of oleic acid is, however, 

 best accomplished by d. The mixture must be well dried and 

 the ether-alcohol made from anhydrous spirit and ether ; 1 part 

 by weight of oleate of soda dissolves in 935, 1 of resinate of soda 

 in 7 '9 parts of ether-alcohol. 



CHLOROPHYLL AND ALLIED SUBSTANCES. 



132. Chlorophyll. Notwithstanding that the chemical nature 

 of chlorophyll is still involved in considerable obscurity, I treated 

 it in 20 as a homogeneous body, and at the same time pointed 

 out that the chlorophyll-granules observable under the microscope 

 contain solid albuminous substances, starch, etc., in addition to 

 chlorophyll. 



It has been satisfactorily proved by Fremy 1 and others that 

 chlorophyll may be separated by treatment with hydrochloric acid 

 and ether or benzene into two colouring matters, one of which, 

 cyanophyll or phyllocyanin, is blue and soluble in ether and 



1 Comptes Rendus, 1. 405,1860, Ixi. 188, 1865; Journ. f. prakt. Chem. 

 Ixxxvii. 319, 1862. See also Kromayer und Ludwig, Archiv d. Phai-m. clvi. 

 164, 1861 ; Ae, Archiv d. Pharni. cxcii. 163, 1870; Kraus, ' Zur Kenntniss 

 de.s Chlorophyllfarbatoffes,' Stuttgart, 1872 ; Wiesner, Chem. Centralblatt, 

 3":i, 1S74 ; Filhol, Comptes Rendus, Ixi. 371, Ixxix. 612, 1874 ; Hartsen, 

 Annal. der Phys. cxlvi. 158, 1874; ' Neue chemische Untersuchungen,' 

 Forstemann, 1875 ; Archiv d. Pharm. [3], vii. 136, 1875. 



8 



