[54] M: pp. 21, 35, 37, 38.

[55] M: pp. 35, 63.

[56] M: pp. 45, 46.

[57] Gilbert's terminology strongly suggests that he was familiar with alchemical literature, as well as that of medical chemistry. He has been credited as being highly skilled in chemistry. See Sir Walter Langdon-Brown, "William Gilbert: his place in the medical world," Nature, vol. 154, pp. 136-139, 1944.

[58] Ibid., p. 37.

[59] M: pp. 35, 36, 53, 59. See also Galen, op. cit. ([footnote 15]) bk. 2, ch. 3.

[60] M: pp. 16, 59.

[61] M: pp. 20, 21, 32, 61, 63, 66, 70.

[62] M: p. 59.

[63] M: p. 84.