In Part IV . of these researches reasons have been adduced for the following general conclusions, viz. that codeia and morphia are capable of forming polymerides (with the elimination of methyl in the case of codeia is some instances), which yield derivatives containing certainly not less than C
68
, and probably not less than C
130
(C
72
and C
144
in the case of those codeia derivatives where methyl has not been eliminated). Experiments now in progress tend to show that the formulae of codeia and morphia are really double of those formerly ascribed to these bases
i, e
. are C
30
H
42
N
2
O
6
and C
30
H
42
N
2
O
6
respectively, the proof of which is (as will be shown in a subsequent communication) that the first products of the action of hydrochloric acid on these bases appear to ‘contain chlorine and carbon in the proportions C
36
and Cl, C
34
and Cl respectively, instead of C
18
and Cl, C
17
and Cl. It might be anticipated, therefore, that intermediate polymerides might be form ed containing respectively :— Morphia series. Monomorphia.. C
34
H
38
N
206
Dimorphia . . . . C
68
H
70
N
4
O
12
Trimorphia.. . . C
102
H
104
N
6
O
18
Tetramorphia.. C
136
H
152
N
8
O
24
Codeia series. C
36
H
42
N
2
O
6
. . . Monocodeia. C
72
H
84
N
4
O
12
. . Dicodeia. C
108
H
126
N
6
O
6
. . Tricodeia. C
144
H
168
N
8
O
24
. . Tetracodeia. In the case of codeia these anticipations have been verified. In order to obtain these supposed polymerides before their alteration by secondary reactions, the action of acids other than a hydro acids was examined. Acetic acid seemed a probable agent for purpose ; but no appreciable quantity of any thing different from in codeia was obtained after sixty-four hours’ digestion a t 100° of one part this base with three parts of glacial acetic acid. On precipitation of product by Na
2
CO
3
in large excess, extraction with ether, and agitation of the ethereal extract with HCl, a crystalline mass was obtained while developed a smell of acetic acid on standing in contact with a slight excess of HCl ; but on analysis this gave numbers agreeing with those required codeia hydrochlorate, and from it nothing different from codeia could't obtained ; probably therefore only a trace of acetyl-codeia was formed.
I. Contributions to the history of the opium alkaloids.— Part V