THE 

 LONDON, EDINBURGH and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] • 



SEPTEMBER 1854. 



XXIII. On the Action of the Ferment of Madder on Sugar, 

 By Edward Schunck, Ph.D., F.R.S^ 



IN a paper read before the Royal Society in 1852tj I have 

 given an account of the nature and results of the peculiar 

 process of fermentation which takes place in madder and its 

 watery extracts, when exposed to a moderate degree of tempe- 

 rature. I have shown that during this process the bitter prin- 

 ciple of madder, to which I have given the name of rubian, is 

 completely decomposed, giving rise to the formation of a number 

 of substances, of which alizarine, the true colouring matter of 

 madder, is the most remarkable. I have stated that this process 

 is not accompanied by the evolution of gas or any of the usual 

 signs of fermentation, that the access of atmospheric air is not 

 necessary for its completion, and that the rapidity with which it 

 is effected is remarkable. Lastly, I have given an account of 

 the properties and composition of the ferment itself, I have 

 shown that, as regards the power of effecting the decomposition 

 of rubian, none of the usual fermentative substances, such as 

 yeast, caseine, &c., are capable of supplying its place, with the 

 sole exception of emulsine, which forms an imperfect substitute 

 for it ; that its composition differs in a marked manner from that 

 of the other bodies of the same class in containing a much smaller 

 proportion of nitrogen ; and that, in short, it must be considered 

 as a substance altogether sui generis. I have given it the name 

 of Erythrosym. 



In the paper just mentioned, I have stated that ^' if this sub- 



* From the Memoirs of the Literary and Philosophical Society of Man- 

 chester, vol. xii. p. 109; read April 4, 1854. 



t Philosophical Transactions for 1853, parti; and Phil.Mag.vol.v.p.410. 

 Phil. Mag. S. 4. Vol. 8. No. 51. Sqtt. 1854. M 



