of the
alkaloids, is a tertiary base, that is, contains no replaceable hydrogen
atoms in its molecule. It shows very close relations to pyridine. When
nicotine vapor is passed through a red-hot tube, it yields essentially
collidine, and, with this, some pyridine, picoline, lutidine, and gases
such as hydrogen, marsh-gas, and ethylene. Heated with bromine water to
120 deg.C. it decomposes into bromoform, carbon dioxide, nitrogen, and
pyridine. When its alcoholic solution is treated with ferricyanide of
potassium it is oxidized to dipyridine, C_{10}H_{10}N_{2}. Potassium
permanganate, chromic or nitric acid oxidises it to nicotinic acid,
C_{6}H_{5}NO_{2}, which is simply pyridine-carboxylic acid,
C_{5}H_{4}N(COOH), and which, distilled over quick-lime, yields
pyridine, C_{5}H_{5}N.

Turning now to the non-volatile and oxygenized bases, we take up first
the opium alkaloids. _Morphine_, C_{17}H_{19}NO_{3}, is a tertiary
amine, and appears to contain a hydroxyl group like phenols, to which
class of bodies it has some analogies, as is shown in its reaction with
ferric chloride. Its meythl ester, which can be formed from it, is
_codeine_, one of the accompanying alkaloids of opium. Besides the
methyl derivative, however, others are possible, and several have been
recently prepared, giving rise to a class of artificial alkaloids known
as _codeines_. Morphine, rapidly distilled over zinc dust, yields
phenanthren, trimethyl-amine, pyrrol, pyridine, quinoline, and other
bases. The action of strong hydrocholoric acid upon morphine changes it
into apomorphine, C_{17}H_{17}NO_{2}, by the withdrawal of a molecule of
water. Ferricyanide of potassium and caustic soda solution change
morphine into oxidimorphine, C_{34}H_{36}N_{2}O_{6}. When heated with
strong potassium hydrate, it yields methylamine.

_Narcotine_, another of the opium alkaloids, when heated with manganese
dioxide and sulphuric acid, is oxidized and splits apart into opianic
acid, C_{10}H_{10}O_{5}, and cotarnine, C_{12}H_{13}NO_{3}. This latter,
by careful oxidation, yields apophyllenic acid, C_{8}H_{7}NO_{4}, and
this, on heating with hydrochloric acid to 240 deg. C., yields
pyridine-dicarboxylic acid, C_{5}H_{9}N(COOH)_{2}. The base cotarnine
also results from the prolonged heating of narcotine with water alone.
In this case, instead of opianic acid, its reduction product meconine,
C_{10}H_{10}O_{4}, is produced.

_Meconic acid_, C_{7}H_{4}O_{7}, which is found in