[373] A very common but random opinion traces Rousseau's insanity to certain disagreeable habits avowed in the Confessions. They may have contributed in some small degree to depression of vital energies, though for that matter Rousseau's strength and power of endurance were remarkable to the end. But they certainly did not produce a mental state in the least corresponding to that particular variety of insanity, which possesses definitely marked features.
[374] Burton, ii. 314.
[375] For an instructive and, as it appears to me, a thoroughly trustworthy account of the temper in which the Confessions were written, see the 4th of the Rêveries.
[376] Letter to the Duke of Grafton, Feb. 27, 1767. Corr., v. 98: also 118.
[377] Ib. v. 133; also to General Conway (March 26), p. 137, etc.
[378] Corr., v. 37.
[379] Corr., v. 88.
[380] See the letters to Du Peyrou, of the 2d and 4th of April 1767. Corr., v. 140-147.
[381] Davenport to Hume; Burton, 367-371.
[382] J.J.R. to Davenport, Dec. 22, 1766, and April 30, 1767. Corr., v. 66, 152.