414 Dr. Schunck on Rubian and its Products of Decomposition. 



These numbers correspond in 100 parts 



I. II. 



Carbon .... 68-60 6859 

 Hydrogen ... 5-32 5-24 



Oxygen. . . . 2608 2617 



I did not obtain a sufficient quantity of verantine in a pure 

 state for the purpose of analysis, but the properties of the sub- 

 stance formed by the action of alkalies on rubian corresponded 

 so exactly with those of the verantine produced by the action of 

 acids, as to leave no doubt of their identity. 



The compound of sugar and baryta, obtained by the action of 

 baryta on rubian, is similar in appearance to the sugar itself. 

 Its colour is light brown, and when dry it is brittle and trans- 

 parent like dried gum or varnish. It exhibits no trace of cry- 

 stalline form. It is more easily reduced to a state of dryness 

 than the sugar itself, and deliquesces much less when exposed 

 to a moist atmosphere than the latter. When its solution is 

 mixed with acetate of lead, the whole of the sugar seems to be 

 precipitated in combination with oxirle of lead. On analysing a 

 specimen of this substance prepared by precipitating the excess 

 of baryta with carbonic acid, 1 obtained the following results : — 



I. 0-6375 grm. heated for several hours in the water-bath, 

 gave 0*5245 carbonic acid and 0-1945 water. 



II. 0-7575 grm. gave 0-6320 carbonic acid and 0-2235 water. 

 0*4860 grm. gave 0-3480 sulphate of baryta, equivalent to 



0*22838 baryta. 



From these numbers may be deduced the following compo- 

 sition : — 



324-2 10000 100-00 



If the baryta contained in the solution of sugar be precipi- 

 tated with sulphuric acid, and the latter be again neutralized 

 with carbonate of baryta, there is obtained, as I mentioned 

 above, a compound of sugar and baryta containing less baryta 

 than the preceding. Its analysis yielded the following results : — 



I. 0*4330 grm. gave 0*4670 carbonic acid and 0*1825 water. 



II. 0*3770 grm. heated for several hours longer at 100^ C, 

 gave 0*4150 carbonic acid and 0*1570 water. 



0*3890 grm. gave 0*1890 sulphate of baryta, equivalent to 

 0-1240 baryta. 



