The long sigh of the Frog — French

The long sigh of the Frog 1
Upon a Summer's Day
Enacts intoxication
Upon the Revery-
But his receding Swell 5
Substantiates a Peace
That makes the Ear inordinate
For corporal release-
(F.1394/J.1359)
[1] Frog:: the French language (OED n.3b).
[3] intoxication:: excitement, entrancement.
[4] Revery:: reverie, a fancy vision, daydream.
[5] Swell:: a sound or succession of sounds gradually increasing in volume (OED 5a). rededing Swell:: reducing his voice.
[6] a Peace:: a kind of peace in ear, but not in mind.
[7] inordinate:: the mismatch of receding volume and increasing excitement.
[8] corporal release:: a physical (not mental) relief.

M. L'Abbe Spallanzani, who has demonstrated that FROGS, by which he means Frenchmen, (substituting, by learned licence, the food for the feeders, as Milton and Euripedes are said, by a Rt. Rev. Critic, to substitute effects for causes, and tears for cinders. ─ The Poems of George Huddesford (1801)