The usual procedure for deriving finite-difference equations consists of approximating the derivatives in the differential equation via a truncated Taylor series.

This is it / That makes the wappened widow wed again / She, whom the spi-house and ulcerous sores / Would cast the gorge at, this embalms and spices / To th' April day again.

Exhibiting flowers in their natural colours embossed upon a purple ground.

Your voice is like a meadowlark / But your heart is like an ocean / Mysterious and dark