ABSORPTION SPECTRA OF THE ALKALOIDS. 
517 
those in which the band is situated, and continues so far down the curve that the 
selective absorption is not made manifest. Narceine appears to be a good example of 
this; its absorptive power is very great, extending into the region of such low 
refrangibility as wave-length 3000 when 1 millim. of liquid is examined containing 
only xoVo °f substance, so that no band is visible. In the case of narcotine and 
oxynarcotine it is difficult to arrive at any conclusion, but, from the extension of their 
absorption bands, it is probable that the portion of the molecule which has a constitu¬ 
tion hitherto undetermined is the principal cause of the absorption. In the case of 
apomorphine the loss of water appears to cause two molecules of morphine to coalesce, 
the result being that the band does not suffer displacement to any great extent; it 
still absorbs rays of approximately the same wave-length, but the band appears far 
down the curve, or, in other words, the intensity of the absorption, is increased. 
The remarks on narceine are also applicable to papaverine in every particular. 
Cevadine. 
Cevadine yields on saponification a new base, provisionally called cevine and 
cevadic or methyl-crotonic acid; its formula therefore as shown by Wright and Luff 
(J. Chem. Soc., vol. xxxiii., p. 351) is the following :— 
(Co 7 H 41 N0 6 ) 
/OH 
\O.CO.C(CH 3 )=C a H 
4 
Veratrine. 
Veratrine [(CogH^NOy) —O.CO.C e H 3 (O.CH 3 ) 3 ] when saponified decomposes into a 
new base and di-methyl-protocatechuic acid. Its curve greatly resembles that of 
codeine and morphine with their derivatives (ibid., p. 355), and is distinctly different 
m character to that of cevadine, as the latter shows no absorption band. At the 
present time, however, no inference is to be drawn from this, for we have no know¬ 
ledge of the constitution of the basic portion of the molecule which is the major part 
in veratrine. 
Brucine and Strychnine. 
The absorption curves of brucine and strychnine are interesting, the former being 
essentially different from the latter, as it extends into a much less refrangible portion 
of the spectrum. It will be observed that the brucine shows two absorption bands, 
the second, however, is very like that of strychnine, so much so indeed as to cast 
suspicion upon the purity of the specimen Of brucine examined. This, however, 
cannot be questioned. (See pp. 519-520.) 
MDCCCLXXXV. 3 X 
