1917.] 



Detection of Lactic and Gly colic Acids. 



28f> 



It represents morphine as a dihydroxy-phenanthrene, con- 

 taining an ether-linked oxj^gen atom and a hydrogenised pyridine 

 nucleus having the nitrogen linked to methyl. The similarity 

 in the behaviour of proteins containing the indole group and 

 of morphine towards formaldehyde, naturally leads us to the 

 search for a group common to both. The reaction in the case 

 of proteins has, as already stated, been explained by Rosenheim 

 as due to the presence of the indole group. Proteins, in which 

 the indole group is absent, do not respond to this test. The 

 behaviour of indole itself, previously mentioned, lends a strong 

 support to the same view. Like morphine it produces a violet 

 colouration with formaldehyde and reddish brown with acetal- 

 dehyde. This leads us to" suggest the presence of an indole 

 group in the morphine molecule. That the production of the 

 colour reaction is due to the presence of a particular group 

 in the morphine molecule is also evidenced by the fact that 

 codeine, whose identity as methyl morphine has been estab- 

 lished bevond doubt, has been found by Deniges {Bull Soc 

 Chim. 1909, iv. 647-49) to exhibit the same colour changes with 



the two Aldehydes. 



I therefore venture to suggest that the Nitrogen atom in 

 Morphine forms part of a five-membered ring, and that its for- 

 mula should be written in such a way as would indicate the 

 presence of an indole group in it. Of the number of formu- 

 las which may be drawn up in this way, the following one 

 seems to be the most preferable as being in accord with the 

 maximum number of the other experimental facts hitherto 

 noted : — 



H 

 C 



OH-C 



CH 



CtH 



ME-N 



Morphine 



Finally 



(J. Pr. Chem. 1907 [ii] 76, 428-432) as a res ™ ^^ has 

 gation of the action of sulphites on pyridine and morp 

 sucrffAQf.^ +i,^ n «™«. formula for the alkaloid. 



suggested 



