The Spanish Gypsy (1868) by George Eliot is a closet drama in blank verse, set in Spain in the late 15th century, during the reign of Ferdinand and Isabella. Duke Silva of Bedmár is engaged to Fedalma, but he knows that his uncle Isidor hopes to prevent the marriage by denouncing Fedalma to the Inquisition, if only he can ferret out some crime or heresy on her part:
“She is not lost to me, might still be mine
But for the Inquisition,—the dire hand
That waits to clutch her with a hideous grasp.
Not passionate, human, living, but a grasp
As in the death-throe when the human soul
Departs and leaves force unrelenting, locked,
Not to be loosened save by slow decay
That frets the universe. Father Isidor
Has willed it so; his phial dropped the oil
To catch the air-borne motes of idle slander;
He fed the fascinated gaze that clung
Round all her movements, frank as growths of spring,
With the new hateful interest of suspicion.”
George Eliot (1868). The Spanish Gypsy, pp. 176–177. Edinburgh: Blackwood.
In this passage, how does the figure of the oil catching the motes work? One part of the figure is straightforward: Isidor is using his position in the church (represented by the phial of holy oil) to pick up gossip about Fedalma, as oil collects dust. But what is Isidor imagined to be doing in the other part of the figure? Under what circumstances would someone drop oil to catch dust?
Update In the terminology of I. A. Richards (The Philosophy of Rhetoric, p. 96 ff.), this is a metaphor in which the tenor makes sense (Isidor is gathering gossip about Fedalma), but the vehicle does not (Isidor is collecting airborne dust by dropping oil). In comments Peter Shor asks, reasonably, whether the vehicle needs to make sense here, but if I knew the answer to that, I wouldn’t need to ask this question! Either the vehicle is nonsensical, or I am ignorant about the context in which it makes sense.