Overview
Chapter 85 of Moby-Dick, titled "The Fountain," is one of 's most philosophically rich cetological chapters. Ishmael marvels that despite six thousand years of observation by humans and centuries of close pursuit by whale hunters, the fundamental nature of the whale's spout remains uncertain—whether it consists of water, vapor, or some mixture of both. This unsolved mystery becomes a springboard for meditations on breathing, knowledge, and the limits of human understanding.
The Whale's Breathing Apparatus
Ishmael explains the respiratory physiology of the Sperm Whale in meticulous detail. Unlike fish, which extract oxygen through gills, the whale possesses lungs like a human being and must surface periodically to breathe through its spiracle—a blowhole atop its head. The whale cannot breathe through its mouth, which is buried eight feet below the waterline and has no connection to its windpipe. Between its ribs, a remarkable "Cretan labyrinth" of blood vessels stores oxygenated blood, allowing the whale to remain submerged for an hour or more—much as a camel stores water for desert crossings. When undisturbed, a Sperm Whale surfaces for a fixed number of breaths (say, seventy) with mechanical regularity, and will insist on completing this full allowance even if alarmed and forced to dive prematurely.
The Mystery of the Spout
The chapter turns to the central question: is the spout water or vapor? Ishmael notes that because the whale has no proper sense of smell and no voice (its windpipe opens only into the spouting canal, not the mouth), these missing faculties may be connected to the spout's mysterious nature. The spouting canal, running horizontally beneath the whale's head, is compared to a gas-pipe and is fitted with valve-like "locks" for retaining air and excluding water. Practical observation proves inconclusive: the spout is always surrounded by cascading seawater, and any apparent moisture could be mere condensation. Whalemen consider the spout poisonous—contact with its outer shreds causes the skin to smart, and closer exposure has peeled skin from a man's cheek and arm. If spouted directly into the eyes, it is said to cause blindness.
Philosophical Reflection
Ishmael ultimately hypothesizes that the spout is "nothing but mist," and elevates this conclusion into a grand metaphor. He compares the whale's vapor to the "semi-visible steam" that rises from the heads of deep thinkers—Plato, Pyrrho, Dante, Jupiter, and the Devil—when engaged in profound contemplation. The image of a whale sailing through a calm tropical sea, its head crowned with a vapor canopy irradiated by a rainbow, becomes a symbol of divine endorsement of thought itself. The chapter closes with one of the novel's most celebrated philosophical passages: "Doubts of all things earthly, and intuitions of some things heavenly; this combination makes neither believer nor infidel, but makes a man who regards them both with equal eye." In this way, the unresolvable mystery of the spout mirrors Ishmael's own epistemological stance—embracing uncertainty as a condition of genuine wisdom.