"Jenny" is quite a long poem that has thirty-four stanzas. It is inspired by one of the scenes from Shakespeare's play called The Merry Wives of Windsor. It is a scene where one of the characters Mistress Quickly does a play of words. The scene goes like this: Schoolmaster sir Evans asks the young William Page to answer the genitive case plural in Latin and William answers with "horum, harum, horum". Mistress Quickly humorously plays on this and says that William said that Jenny is a whore and asks for "Vengeance of Jenny's case".
This famous line is quoted at the beginning of the poem Jenny. What's interesting is that the last part of the line "whore" is omitted from the poem. In fact, the poet never uses the words like whore or harlot to describe Jenny. This creates the power of suggestion, which intensifies the meaning of the poem more then just blatantly using those words. The poem is about the life of the harlot Jenny said from a perspective of one of her customers who is the speaker of the poem as well. Jenny is a completely passive character of the poem and we don't hear her voice at all, so we get a completely male view of her life.