[20] A similar piece of mechanism had been previously made by M. le Droz.
[21] See Letter XI.
[22] Had M. Kempelen known the modern discovery of giving glue any degree of softness, by mixing it with molasses or sugar, which is always absorbing moisture from the atmosphere, he might have obtained a still more perfect imitation of the human organs.
[23] See Edinburgh Journal of Science, No. viii., p. 200.
[24] Description of Volcanoes, p. 170.
[25] Edinburgh Journal of Science, New Series, No. i., p. 124.
[26] Considerations on Volcanoes, and Edinburgh Journal of Science, No. xx., p. 261, and No. xiv., p. 265.
[27] Art. Sound, Encycl. Metrop., § 110.
[28] Edinburgh Journal of Science, No. xvii., p. 158.
[29] Revue Encyclopédique, 1821, tome ix., p. 592.