It is the residue of animal and vegetable putrefaction, and is a black body; when dry it is pulverulent, and when wet has a soft, greasy feel... It is the produce of organic power—a compound of carbon, hydrogen, nitrogen, and oxygen, such as cannot be chemically composed.
p. 336; Cited in: Edmund Ruffin An Essay on Calcareous Manures, Volume 1. J.W. Randolph, 1852. p. 85. - The Principles of Agriculture, 1844 - Section III: Agronomy