458 MR. SCHUNCK ON RUBIAN AND ITS PRODUCTS OF DECOMPOSITION. 
To this view however it may be objected that all the species of sugar capable of 
fermentation with which we are acquainted contain 12 equivs. of carbon. Indeed it 
is difficult to conceive how a body of the formula 0^4 H14 0^4 can be decomposed into 
alcohol and carbonic acid. It is therefore far more probable that the formula of this 
substance is C12 H42 0^2, which is also that of grape-sugar when dried at 100° C. In 
fact, were it capable of being crystallized, it would no doubt be considered as iden- 
tical with grape-sugar. If this be granted, then it follows that the formula of rubia- 
nine must be either C32 O45 or C44 H24 O20, as will be seen by the following equa- 
tions : — 
or 
2 equivs. of Sugar . . 
— C24 H24 O24 
1 equiv. of Rubianine . 
= €32 H|9 0^5 
^56 ^^43 ^39 
1 equiv. of Sugar . . 
= Ci2 Hi2 ^12 
1 equiv. of Rubianine . 
— C44 H24 O20 
^56 ^35 O32 
Cgg H34 030= 1 equiv. of Rubian. 
H 9 O 9=9 equivs. of Water. 
^56 ^43 O39 
jCgg H34 039=1 equiv. of Rubian. 
1 H 2 O 2=2 equivs. of Water. 
^56 ^36 ^32 
The formula C44 H24 O20 seems to me the more probable of the two. It agrees best 
with the results of analysis, and the high atomic weight of rubianine which follows 
from it explains the very neutral character of that substance. Hence it appears that 
rubianine stands in the same relation to the sugar as rubiretine does to verantine. 
When added together they contain the elements of rubian plus the elements of water, 
while rubiretine and verantine added together contain the elements of rubian minus 
the elements of water. 
On the whole, it appears that the action of acids on rubian is not of so complicated 
a nature as might at first sight be supposed. The number of substances produced 
by this action is five. Nevertheless it does not follow that these five substances are 
all formed together, or in other words, that one atom of rubian by its decomposition 
gives rise to all five at the same time. From the composition of these substances, as 
compared with that of rubian, it follows that the latter by the action of acids under- 
goes decomposition in three different directions, or more correctly speaking, that the 
decomposition affects three separate atoms of rubian. One of these atoms loses 
14 atoms of water, and is converted into alizarine. The second loses 12 atoms of 
water, and then splits up into verantine and rubiretine. The third takes up the ele- 
ments of water, and then splits up into rubianine and sugar. What the circumstances 
are under which either one or the other of these three processes takes place I am 
unable to say. That the loss of a greater or smaller proportion of water or the addi- 
tion, on the contrary, of the elements of water to those of rubian, are the immediate 
efficient causes of one or the other of the three processes taking place is very pro- 
bable ; but what again determines the elimination of more or less water from rubian, 
or, on the other hand, its combination with more water, remains uncertain. It is not 
