440 DR ANDERSON ON THE COLOURING MATTER ' 



100-00 100-00 



Tliese analyses give the formula Cjs H,; Oj „ which agrees perfectly with the 

 mean of the experimental results, as is shewn by the following calculation. 



Calculation. Mean of Experiment. 



28 Equivalents Carbon, . . . 2100-0 5544 55-41 



15 •■• Hydrogen, . . 187-5 4-95 5-11 



15 ••• Oxygen, . . . 15000 39-61 39-48 



3787-5 10000 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? H4 Oj. 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 

 Cog Hi„ Oui, 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 Schiel, being C,,,HioO|5. 



Moreover, this similarity is not confined to their formulae only, but extends 

 itself over all their jihysical 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 is a 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- 

 chonacese, which, by many botanists, is considered as merely a section of the Ru- 

 biacese, 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 iinJ Phariiiaeie. vol. Ix., p. 74. 



