are hydrolyzed they yield
quinoline and indole, their composition is unknown.

=Morphine=, C_{17}H_{19}NO_{3}, is the chief alkaloid of opium, which is
the dried juice of young pods of the poppy. Both the alcoholic solution of
opium (known as "laudanum") and morphine itself are extensively used in
medicine as narcotics to deaden pain. Morphine has an exceedingly complex
structure, being a combination of an isoquinoline and a phenanthrene
nucleus, which is probably correctly represented by the following formula:

H H_{2}
| |
C C
// \ / \
HOC C CH_{2}
| | |
C C N-CH_{3}
/ \\/ \ /
/ C CH
O | |
\ HC CH_{2}
\ / \ /
HC C
| |
H_{2}C CH
\ /
C
|
H_{2}

=Codeine=, C_{17}H_{18}(OCH_{3})NO_{2}, which is also found in opium, is a
methyl derivative of morphine. =Papaverine=, =laudanosine=, =narcotine=,
and =narceine= are four other alkaloids found in opium. They each contain
an isoquinoline nucleus, combined by one bond to a benzene ring, with one
or more methyl groups and three or more methoxy (OCH_{3}) groups attached
at various points around the three characteristic rings. The following
formula for laudanosine will illustrate their structure:

/ \ / \
CH_{3}O | |
| | | OCH_{3}
CH_{3}O | N-CH_{3} / \
\ / \ / | |OCH_{3}
| | |
| \ /
H_{2}C----------------CH

The above discussions of the composition of typical alkaloids clearly
indicate the extreme complexity of their molecular structure. It is
gene