In two distinct instances near the beginning of Heart of Darkness,
Marlow describes the Congo river as a snake. The first time is as he is
deciding to go into the Congo, when he sees the map of Africa in the
shop window. He elaborates on the metaphor of the snake, saying the
river resembled “an immense snake uncoiled, with its head in the sea,
its body at rest curving afar over a vast country, and its tail lost in
the depths of the land.” This image is repeated for emphasis while he is
in the Company’s office in Brussels, again looking at a map of Africa.
There he calls the river “fascinating--deadly--like a snake.”
The image of a snake is an ancient one rich in symbolism. Generally, it represents evil, “darkness” as the book’s title suggests, and fittingly the Company men along the river are dark and corrupted. However, snakes also hold a seductive or tempting element--Marlow says “the snake had charmed me” at one point. As Marlow is an explorer by nature, this snake-like river tempts him to enter it, offering him greater knowledge of the world--but at a price. Marlow is clearly changed by this experience, having greater knowledge not only of Africa as a place but of the violent and exploitative goings-on there. In this sense, Heart of Darkness mimics the biblical story of the garden of Eden, one of the richest, most commonly alluded-to sources of snake symbolism in the Western world.