422 



BRITISH PHARMACEUTICAL CONFERENCE, EXETER. 



Cinchona sue- 

 cirubra. 



Madder. 



1869. the third time renewed is better fitted for the extraction of 

 quinine than normal bark, and yields the alkaloid in a state in 

 Broughton on which its purification is singularly easy. 



Mr. Broughton, whose assiduity in this field of research con- 

 tinues unabated, made experiments on two trees of Cinchona 

 succirubra, which showed that when the trunks were deprived of 

 light for some months by being covered with tinned plate 

 or black cloth, the amount of alkaloids increased 50 per cent. ; 

 the proportion of quinine, however, remained almost stationary, 

 the increase being in the shape of cinchonine and cinchonidine. 

 In bark renewed under moss, an improved proportion of quinine 

 is found. 



The cultivators of madder are in the habit of covering up 

 with earth the lower portion of the stems of the plant, finding 

 by experience that deprivation of light tends to develop the 

 peculiar colouring matter for which the plant is valued. It has 

 been observed by Decaisne in examining microscopically the 

 roots and stems of madder, that the cellular tissue of the former 

 contains a yellow liquid, while the latter is filled with green 

 colouring matter ; and he has been able to prove by experiment 

 that it is possible to change at discretion the production of 

 chlorophyll and to cause the elaboration of the colouring matter 

 of the root in its place. It happens in this case, observes Mr. 

 Howard, that the green portions which when exposed to light, 

 absorb the carbonic acid of the air whilst disengaging oxygen, 

 absorb, on the contrary, when deprived of light, the oxygen of 

 the atmosphere which surrounds them and replace it with car- 

 bonic acid. Does not something analogous take place in the 

 red bark tree, the shading of the stem of which is attended 

 with such manifest advantage ? 



In Mr. Broughton's Eeport to the Madras Government, the 

 following interesting fact is related: among the Crown-bark 

 trees (Cinchona officinalis, L.) raised from seeds collected by Mr. 

 Cross, there were observed to be a few having narrow, lanceolate 

 leaves and a somewhat different aspect from their companions. 

 A comparative analysis of the bark of these two forms of Cinchona 

 (growing side by side and raised, as it would seem, from the same 



Madras 

 report. 



