440 DR ANDERSON ON THE COLOURING MATTER ' 


Ti 106 ai. 
Carbon, irc tie WOO EG 55°40 55°39 
Hydrogene in LO 5°03 . 
Oxygen, 2 gs, OOOO 39°57 
100-00 100-00 
These analyses give the formula C,,H,;0,,, which agrees perfectly with the 
mean of the experimental results, as is shewn by the following calculation. 


Calculation. Mean of Experiment. 
SS 
28 Equivalents Carbon, . . . 2100°0 55°44 55°41 
15 vs Hydrogen,) 2*) 21675 4:95 511 
15 wee Oxygen, /)/ 2/1 F500 39°61 39°48 
3787'5 100-00 100-00 
The formula thus ascertained brings out an interesting relation between mo- 
rindine and the colouring matters of madder, and more especially that one which 
is obtained by the sublimation of madder purple. From his analysis of this sub- 
stance, ScHIEL* deduces the formula C, H,O,. As this, however, is no more than 
the simplest expression of the analytical results, and as all the other madder 
colouring matters examined contain 28 equivalents of carbon, we are justified in 
supposing its real constitution to be represented by quadruple of that formula, or 
C.,H,,O,,. which differs from that of morindine by a single equivalent of water 
only. The unsublimed madder purple is also connected, though more remotely, 
with morindine, and differs only by containing 5 equivalents of hydrogen less, 
its formula, according to ScHzEL, being C,; Hy) O.;. 
Moreover, this similarity is not confined to their formule only, but extends 
itself over all their physical and chemical properties, which approximate very 
closely, although they are sufficiently distinct to preclude the possibility of their 
being confounded with one another. And this isa point well worthy of observa- 
tion, as illustrating the similarity in chemical constitution of plants so nearly re- 
lated in the botanical system; the morinda belonging to the natural family Cin- 
chonaceze, which, by many botanists, is considered as merely a section of the Ru- 
biaceze, of which madder is the type. 
This similarity, however, does not extend itself to their properties as dyes, in 
which respect they differ in a very remarkable manner. I have already men- 
tioned that the calico-printers had entirely failed in producing a colour by means 
of sooranjee; and this I have fully confirmed as regards the common mordants. 
I digested morindine for a long time, in a gradually increasing heat, with small 
pieces of cloth mordanted with alumina and iron, but nothing attached itself, and 
* Annalen der Chimie und Pharmacie, vol. lx., p. 74. 

