"Semitic guess"

[Geoffrey Nunberg]

The following passage is from Browning's "Sordello, Strafford,
Christmas-eve and Easter-day" (1864). Does anybody have any idea what
a "Semitic guess" was, or whether it was a generally used expression?
I haven't been able to find other hits for the phrase.

Geoff Nunberg


So, I would rest content
At him, above all epitaphs
Aspires to have his tomb describe
Himself as Sole among the tribe
Of snuff-box-fanciers, who possessed
A Grignon with the Regent's crest.
So that, subduing, as you want,
Whatever stands predominant
Among my earthly appetites
For tastes, and smells, and sounds, and sights,
I shall be doing that alone,
To gain a palm-branch and a throne,
Which fifty people undertake
To do, and gladly, for the sake
Of giving a Semitic guess,
Or playing pawns at blindfold chess.