1864.] 



Dr. Stenhouse on Rubia munjista. 



145 



is rather hinted at than described, I can only conjecture what the sub- 

 stance is ; but I suppose it to be a mixture of the second yellow substance 

 with the products of decomposition of the other three bodies. Green sea- 

 weeds {ChlorosjpermecB) agree with land-plants, except as to the relative 

 proportion of the substances present ; but in olive-coloured sea-weeds {Me- 

 lanosjpermecE) the second green substance is replaced by a third green sub- 

 stance, and the first yellow substance by a third yellow substance, to the 

 presence of which the dull colour of those plants is due. The red colouring- 

 matter of the red sea-weeds {RhodospermecE) , which the plants contain in 

 addition to chlorophyll, is altogether [different in its nature from chloro- 

 phyll, as is already known, and would appear to be an albuminous substance. 

 I hope, before long, to present to the Royal Society the details of these 

 researches. 



Continuation of an Examination of Rubia munjista, the East- 

 Indian Madder, or Munjeet of Commerce." By John Sten- 

 house, LL.D., F.R.S. Received December 21, 1863 



In the former, preliminary notice of the examination of the Rubia mun- 

 jista f, the mode of extracting munjistine from munjeet, and a number of 

 its properties, have been already described. I now proceed to detail some 

 results which have been subsequently obtained. 



'V\Tien munjistine is extracted from munjeet by boiling solutions of sul- 

 phate of alumina, as the whole of the colouring matter is not extracted by 

 a single treatment with the sulphate of alumina, the operation must be 

 repeated five or six times instead of two or three as was formerly stated. 

 During the boiling of the munjeet with sulphate of alumina, a large quantity 

 of furfurol is given off. I may mention, in passing, that the most abundant 

 and economical source of furfurol is found in the preparation of garancine 

 by boiling madder with sulphuric acid. If the wooden boilers in which 

 garancine is usually manufactured were fitted with condensers, furfurol 

 might be obtained in any quantity without expense. 



In addition to the properties of munjistine already described, I may 

 mention that acetate of copper produces in solutions of munjistine a brown 

 precipitate but very slightly soluble in acetic acid. 



When bromine-water is added to a strong aqueous solution of munjistine, 

 a pale-coloured flocculent precipitate is immediately produced ; this when 

 collected on a filter, washed and dissolved in hot alcohol, furnishes minute 

 tufts of crystals, evidently a substitution-product. Unfortunately these 

 crystals are contaminated by a resinous matter, from which I have been 

 unable to free them, and therefore to determine their composition. 



When munjistine is strongly heated on platinum foil, it readily inflames 

 and leaves no residue ; when it is carefully heated in a tube, it fuses, and 

 crystallizes again on cooling. If heated very slowly in a Mohr's apparatus, 



* Read January 14. See Abstract, page 86. f Proceedings, vol. xii. p. 633. 



