One can either produce a straightforward picture
Or else what is known as a negative one.
In the latter the lights and the shades are reversed,
And they’re apt to seem ugly to commonplace eyes;
But for all that the likeness is latent in them,
And all you require is to bring it out.
If, then, a soul shall have pictured itself
In the course of its life by the negative method,
The plate is not therefore entirely cashiered,—
But without more ado they consign it to me.