Dr. Schunck on Ruhian and its Products of Decomposition. 275 



the following comparison between the theoretical composition 

 and the experimental results will show : — 



Carbon 



Hydrogei)^ 



Chlorine 



Oxygen 



Baryta 



1475^ 100-00 



The sugar which is formed from chlororubian together with 

 chlororubiadine may be obtained in a crystallized state, which is 

 not the case with the different specimens of sugar derived from 

 the other processes of decomposition to which I have subjected 

 rubian. If sulphuric acid be employed for the decomposition of 

 chlororubian, and the acid after filtration of the flocks of chloro- 

 rubiadine be neutralized with carbonate of lead, the filtered 

 liquid yields on evaporation a sweet syrup. If this syrup be 

 treated with alcohol, a part of it dissolves with a yellow colour. 

 If the alcoholic solution, after separation from the insoluble 

 part, be mixed with several times its volume of aether, it becomes 

 milky and deposits again a yellow syrup, which after standing 

 some time becomes filled with small yellowish crystals, so as 

 almost to form a solid mass. This mass is pressed between 

 blotting-paper, in order to remove the mother-liquor, and the 

 crystals are dissolved in boiling alcohol, to which a little animal 

 charcoal is added. The filtered solution on evaporation gives a 

 syrup, which is soon converted into a mass of white crystals. 

 These crystals have the properties and composition of crystal- 

 lized grape-sugar. 



0-5015 grm. of the crystals, dried in vacuo ^ gave 0-6830 car- 

 bonic acid and 0-3380 water. 

 ^j«Itiese ^l^|^l[^ers lead to the following composition : — 



1^ 198 10000 10000 



t It will now admit, I think, of little doubt, that the uncrystal- 

 lizable sugar obtained from rubian in other processes of decom- 

 position is merely modified grape-sugar. 



The formation of chlororubiadine and sugar from chlororubian 

 is a very simple process. The latter loses three equivalents of 

 water and splits up into chlororubiadine and sugar, as will be 

 evident from the following equation : — 



C'^H27C1024^C^2Hi2C109 4.Ci2Hi2 0»2-f3HO^ax{i' ' 

 T2 ' 



