Tom Colket later wrote:
The tarot cards, despite the bogusness of Madame Sosostris, appear to correctly predict important characters and events in the poem, presumably characters and events that deeply affect the narrator. For example, "Belladonna" is likely the first woman depicted in "A Game of Chess". Why is the merchant explicitly called out by the tarot cards? When he finally appears in the poem, he has fewer lines than Phlebas in "Death by Water". Marie doesn't rate a tarot card, and neither does Stetson. What makes Eugenides so important to the narrator that he is part of the tarot pack introduction?
"And here is the one-eyed merchant, and this card,   
 Which is blank, is something he carries on his back,  
 Which I am forbidden to see."
Three things immediately strike me that make the merchant such an essential part of Eliot's design of The Waste Land.
1. The knowledge of the fertility cults which the Phoenician sailors and merchants were famed to bring with them -- this knowledge could help prevent a waste land condition or dispel its curse. The merchant here, ironically, does the opposite -- he is, instead, spreading the sterile cult of homosexuality.
2. He is fitly described as "one-eyed" -- the eye of "profit and loss" -- his other eye, the eye that can perceive the ultimate, the true, the metaphysical dimension of life, is blind. He is blind to the mysteries and miracles that the knowledge of fertility cults can achieve.
3. The card that is blank, that he is carrying on his back, is the card of the fertility cults and their miraculous powers -- quite tellingly, this card is now "blank".
The passage about Euginedes inviting the narrator to a weekend etc. is precisely aimed at showing how these phoenician merchants spread the sterile cult of homosexuality instead of the fertility cults etc.
The section on Death by Water shows how only a "death by water" (one can expostulate on that) can salvage the merchant's fate -- and help him "[forget] the profit and the loss"
and bring about a transmutation etc.

--- On Mon, 5/10/10, Chokh Raj <[log in to unmask]> wrote:
Since an attempt is being made to read biography in Eliot's poetry, here's an observation that should be apropos:
According to Matthiessen, one cannot understand Eliot without reckoning with the Puritan mind -- its absorption in the problem of belief, its trust in moments of vision, its dread of vulgarity, its consciousness of the nature of evil, its understanding of the consequences of loneliness and repression, its severe self-discipline and tenderness. One must also take into account Eliot's unusual detachment which reverberates with loneliness but which brings with it in compensation a special development of spiritual understanding.  [F.O. Matthiessen, "The Achievement of T.S. Eliot"]

--- On Mon, 5/10/10, Chokh Raj <[log in to unmask]> wrote:
"Unreal City   
  Under the brown fog of a winter noon  
  Mr. Eugenides, the Smyrna merchant  
  Unshaven, with a pocket full of currants
  C..i.f. London: documents at sight,  
  Asked me in demotic French  
  To luncheon at the Cannon Street Hotel  
  Followed by a weekend at the Metropole."
"This music crept by me upon the waters"
 [And along the Strand, and up the ghastly hill of Cannon Street,
  Fading at last, behind my flying feet]
One might explain the "flying feet" here in two ways:
1. A person, especially one endowed with a puritanical and metaphysical sensibility ("Unreal City"), would run away from something that that person considered evil -- in this case, the "ghastly" hill of Cannon Street.
2. Generally, a walk up the hill is arduous and slow, a walk down perforce fast and brisk. 
Put simply, the widely pervasive sensual music ["this music"] kept resonating in the narrator's ears through his long-winded excursion through the waste land [here of London] -- receding, finally, only after he got fast farther from the "ghastly" hill.
Since Euginedes, the Smyrna merchant, had shown the audacity [in the narrator's eyes] to invite him, a person of puritanical sensibility,  to places notorious as homosexual haunts, the narrator would be doubly wary passing through, what appeared to him, a place of evil and sin. The sensual music
("This music") around the "ghastly" hill would, of course, resound as dissolute to his puritanical ears as the depraved tumult of Carthage to Augustine's ears.
"This music crept by me upon the waters"
And along the Strand, up Queen Victoria Street...
Down Greenwich reach
Past the Isle of Dogs.
Weialala leia
Wallala leialala"
"la la
 To Carthage then I came"
[Eliot's Note: St. Augustine's Confessions: "to Carthage then I came, where a cauldron of unholy loves sang all about mine ears."]