504 



Dr. C. R, A. Wright on the Action of [June 15, 



be included in one common family, and that the separation of the latter 

 from the former as a group of Gymnosperms, as suggested by M. Brong- 

 niart, must be abandoned. The remarkable development of exogenous 

 woody structures in most members of the entire family indicates the 

 necessity of ceasing to apply either to them or to their living representa- 

 tives the term Acrogenous. Hence the author proposes a division of 

 the vascular Cryptogams into an exogenous group, containing Lycopo- 

 diacece, Equisetacece, and the fossil Calamitacece, and an endogenous 

 group, containing the ferns ; the former uniting the Cryptogams with the 

 Exogens through the Cycadece and other Gymnosperms, and the latter 

 linking them with the Endogens through the Palmacece. 



V, "Contributions to the History of the Opium Alkaloids. — Part 

 II. On the Action of Hydrobromic Acid on Codeia and its de- 

 rivatives." By C. R. A. Wright, D.Sc, Lecturer on Chemistry 

 in St. Mary's Hospital Medical School. Communicated by Dr. 

 H. E. Roscoe. Received June 7, 1871. 



It has been shown in Part I. of this research * that the action of hy- 

 drobromic acid on codeia gives rise, without evolution of methyl bromide, 

 firstly to bromocodide, and secondly to two other new bases termed re- 

 spectively deoxycodeia and bromotetracodeia, the latter of which, under 

 the influence of hydrochloric acid, exchanges bromine for chlorine, yielding 

 a corresponding chlorinated base, chlorotetracodeia ; when, however, the 

 action of hydrobromic acid is prolonged, methyl bromide is evolved in 

 some little quantity. By digesting codeia with three or four times its 

 weight of 48 per cent, acid for five or six hours on the water-bath, vapours 

 were evolved which condensed by the application of a freezing-mixture to a 

 colourless mobile liquid, the boiling-point of which was found to be 10° 5 

 to 11 0, 5, and the vapour of which burnt with a yellow-edged flame, and 

 exploded violently with oxygen, forming carbonic and hydrobromic acids. 

 It becomes, therefore, of interest to examine in detail the action of hydro- 

 bromic acid on each of the three bodies produced from codeia under its 

 influence. 



§ 1 . Action of Hydrobromic Acid on Bromotetracodeia, 



. When bromotetracodeia hydrobromate is heated in a sealed tube to 100° 

 with four or five times its weight of 48 per cent, hydrobromic acid for from 

 six to ten hours, methyl bromide is found as a thin layer on the top of the 

 tarry contents of the tube after cooling ; by dissolving this tarry substance 

 in water and fractionally precipitating the liquid by strong hydrobromic acid 

 several times successively, nearly white amorphous flakes are ultimately 

 obtained, resembling in all their physical and chemical properties the bro- 

 motetracodeia hydrobromate originally employed. After desiccation, first 



* Proo. Roy. Soc. vol. six. p. 371. 



