What literary devices are used in Heart of Darkness?

In Heart of Darkness, Conrad uses a frame story to introduce the central plot of Marlow's trip up to Congo River to find Kurtz. This introduces the main tale in eery light and justifies Marlow heightening elements of it to make them more poetic in service of a sailor's gripping yarn. Since the Nellie is on the river Thames in the frame story, this also allows Marlow to universalize the idea of colonial exploitation by ruminating that the blue skinned Britons the Romans once met in ancient times were equally exploited as the Blacks in the Congo. Evil, Marlow argues, is a recurrent darkness in the heart of mankind.

Conrad uses many literary devices to heighten the drama of the tale. He has Marlow, for example, use a simile when he compares the Congo to the "earliest beginnings" of the earth and use a metaphor to liken the "big trees" to kings:

Going up that river was like travelling back to the earliest beginnings of the world, when vegetation rioted on the earth and the big trees were kings.

Later in the passage, Marlow uses visual imagery and alliteration in the line:

On silvery sandbanks hippos and alligators sunned themselves side by side.

Marlow also uses an aphorism or pithy statement as well as personification when he states the silence around him was not peaceful but instead:

It was the stillness of an implacable force brooding over an inscrutable intention.

The line also uses assonance in the repeated "i"sounds, and is typical of the interiority on Marlow's part that permeates the text.

Throughout his story, Marlow uses the extended metaphor of comparing his time in the Congo to a dream.

All of this not merely ornamentation but central to saturating the reader in an intense mood of gloom, unease, and otherness that reflects both the setting and Marlow's frame of mind.

What are three examples of racist literary devices used in Conrad's Heart of Darkness?

Heart of Darkness has been criticized for its racist depictions of Africans. Throughout this novel, native Africans are often portrayed as stupid, superstitious, and primitive. As such, Africans in this story are presented as the antithesis of "civilized" Europeans. Let's look at some examples where Joseph Conrad does this using literary devices.

Throughout his journey up the river, Marlow sees many things that he views as ugly. The Africans are no exception. At one point, he uses a simile to describe what he considers the inhuman faces of the people he sees:

They shouted, sang; their bodies streamed with perspiration; they had faces like grotesque masks— these chaps.

In some ways, Marlow's river journey is meant to symbolize a journey into the underworld, echoing the works of Dante, Homer, and Virgil. Yet, if the Congo is hell, then the people there are stand-ins for demons, devils, and the lost souls of sinners. In one example, Conrad uses metaphors to dehumanize the Africans, reducing them to no more than the plight from which they suffer.

They were not enemies, they were not criminals, they were nothing earthly now, nothing but black shadows of disease and starvation lying confusedly in the greenish gloom.

There are several passages in Heart of Darkness that paint Africa as a primordial and uncivilized land. To Marlow, the people there are little more than animals, and the narrator appears to want to reassure Europeans that they are superior by drawing comparisons. There are several examples, such as the following, in which the land itself is degraded using metaphors, as well as some hyperbole, that describe it as some sort of uncivilized place devoid of reason. The implication here is that the people of this land are no more than primitive savages, so very unlike the refined people of Europe.

We were wanderers on a prehistoric earth, on an earth that wore the aspect of an unknown planet. We could have fancied ourselves the first of men taking possession of an accursed inheritance, to be subdued at the cost of profound anguish and of excessive toil. ...

The prehistoric man was cursing us, praying to us, welcoming us—who could tell? We were cut off from the comprehension of our surroundings; we glided past like phantoms, wondering and secretly appalled, as sane men would be before an enthusiastic outbreak in a madhouse.