A metaphor is a comparison of two things, often using a sensory image to describe an abstract concept. Usually it is differentiated from a simile, which is a comparison using "like" or "as," but a simile is actually a form of metaphor. Here, I will point out metaphors that are not similes:
Henry Jekyll writes in his "full statement of the case" that his soul is characterized by:
even a deeper trench than in the majority of men, [which] severed in me those provinces of good and ill ...
In other words, he is picturing the dual nature of good and evil, which he argues exists in all men, as in his case separated by a wide "trench" in his soul. We can visualize the trench, a metaphor, as a deep ditch dug into the ground, keeping apart the two sides of his nature.
Later, he writes:
I have been doomed to such a dreadful shipwreck ...
In this case, he is using the metaphor of comparing truth to a shipwreck. The truth which has caused a metaphoric shipwreck in his life is the knowledge of the two sides of human nature.
Still feeling depressed, Jekyll writes:
the doom and burthen of our life is bound for ever on man’s shoulders ...
Here, he uses the metaphor of life's unhappiness and tragedy ("doom and burthen") as a pack bound on to the back of each individual.