1917.] 



'/ 



283 



maldehyde and concentrated sulphuric acid is a characteristic 

 test for certain classes of proteins. The reaction in the case of 

 proteins has been explained by Rosenheim as due to the previ- 

 ous formation of a protein-aldehyde compound and its sub- 

 sequent oxidation. Tt has been supposed to depend on the 

 presence of the indole or tryptophane group in the molecule. 

 Proteins, like gelatin, in which the tryptophane or indole group 

 is absent cannot by any means be made to respond to this test. 



CH 



CH 

 CH 



CH 

 CH 



CH 



N 

 H 



Indole. 



Acree also accepts Rosenheim's view of the mechanism of the 

 reaction. The above facts naturally lead us to the interesting 

 question : Does morphine which produces a violet coloration 

 with formaldehyde, contain an indole group in its molecule ? 

 The constitution of morphine which has the empirical formula 

 C n H l9 0,N has not up till now been established beyond 

 doubt. "That it contains a phenanthrene nucleus in its mole- 

 cule has been proved by the recent researches of Vongcrichten 



CH 



C.CH 2 CH(NH 2 )C00H 



Tryptophane or Indole-Aminopropionic acid 



and Schrotter. The large amount of phenanthrene yielded by 

 morphine, when the latter is distilled with zinc dust, goes to 

 support the same fact. It has also been cone usively : shewn 

 that of the three oxygen atoms two are hydros; yhc tod loftfreae 

 two again, one phenolic, and the other alcoholic in chanwten 



Regarding the Lture ^^S^S 

 *e have very little of positive evidence 

 has therefore been assumed to be pr< 

 group. 



very little ot positive evjucixv^- — „w»iwlridi» 



•efore been assumed to be present as an anhydi ide 

 Morphine is a tertiary base, for on treatment with 



