Venice's great trading quarter is an unlikely place to begin a love poem, but the first line sets up shop there: "The soul's Rialto hath its merchandise." From the Rialto the speaker borrows a stock of money words, "barter," "mart," "argosies," and applies them to something no market could price: a lock of hair, swapped "curl for curl" with the man she loves. The central idea is that this small keepsake outweighs whole fleets of merchant ships, and that she will keep it warm for as long as she lives. Trade is only a metaphor. What really changes hands is devotion.
The first eight lines make the lock grander still by giving it a classical pedigree. She calls her beloved "my poet," then reaches for the ancient Greek poet Pindar, to whom the "dim purpureal tresses" of the Muses seemed to fall across their "white Muse-brows." The contrast of "purply black" against white is vivid, and "purpureal" is a rich, rare word that sounds as dark as it looks. Then the logic wobbles, charmingly. The shade of the poet's laurel crown, she guesses, "still lingers on thy curl, it is so black!" The ellipsis after "counterpart" and the breathless exclamation make her sound caught mid-thought, half arguing, half gushing. Black hair becomes the trace of poetic glory, a shadow left by a crown he may not yet wear.
The sestet turns from display to tenderness. She ties the lock with "a fillet of smooth-kissing breath." A fillet is a ribbon or headband, and here the ribbon is a kiss, something no merchant could weigh. Calling the hair "shadows" that might go "gliding back" makes the curl seem almost alive, ready to slip home to his forehead, so tying it becomes an act of capture. The closing lines carry a vow. The lock is laid "here on my heart, as on thy brow, to lack / No natural heat." The line break after "lack" leaves the word hanging, as if loss were briefly possible, before the sentence reassures us. The promise runs only "till mine grows cold in death." Death appears just once, in the final words, and it sets a quiet, honest limit on the promise after all the extravagant hyperbole.
The construction supports this movement. The rhyme scheme is Petrarchan: abbaabba in the octave, then cdcdcd in the sestet, all in iambic pentameter. In the octave, "merchandise," "argosies," "eyes" and "surmise" chime together, which gives the opening its formal, almost ceremonial ring. In the sestet, "black," "back" and "lack" pair with "breath," "hindereth" and "death." That last pairing places "breath" and "death" at opposite ends of one rhyme, binding life to its ending. The old-fashioned diction, "hath," "erst," "athwart," "thy," adds to the ritual feel, as if the exchange of curls were a ceremony with its own language. Compound words such as "smooth-kissing" and "Muse-brows" pack two ideas into one beat, so the lines feel dense but never heavy.
What makes the poem worth reading is how much it fits into fourteen lines. It joins the marketplace, Greek myth and a kiss without any of them feeling out of place. It flatters the beloved by placing him among the Muses and laurel crowns, yet it ends on something small and physical: a curl of hair resting against a beating heart, kept from going cold. The numbered title suggests one poem in a longer sequence, but it also stands well alone, as a study in how an ordinary keepsake can carry more feeling than a harbour full of ships.