chapter 61

, page 621.

[61] I refute this theory, however, in Appendix II to the chapter on Bacon.

[62] Reinaud et Favé, _Le feu grégeois et les origines de la poudre à canon_, (1845) p. 210. In the quotation from Christine de Pisan at pp. 219-20, however, it seems to me that she has reference only to the poisons last-named and not to the Greek fires previously named in declaring them inhuman and against all the laws of war.

[63] _Ibid._, p. 128.

[64] The questions thus far listed occur in the order of mention in the following chapters: 6, 7, 10, 11, 20, 12, 30, 36, 37, 38, 39, 40, 46.

[65] _Quest. nat._, cap. 31.

[66] _Quest. nat._, cap. 21.

[67] _De architectura_, V, iii, 6 (Morgan’s translation). “Voice is a flowing breath of air, perceptible to the hearing by contact. It moves in an endless number of circular rounds, like the innumerably increasing circular waves which appear when a stone is thrown into smooth water, and which keep on spreading indefinitely from the center unless interrupted by narrow limits, or by some obstruction which prevents such waves from reaching their end in due formation. When they are interrupted by obstructions, the first waves, flowing back, break up the formation of those which follow.”

[68] _Quest. nat._, cap. 22.

[69] See above, chapter 5 , vol. I, page 191.

[70] _Quest. nat._, cap. 23.

[71] See above, chapter 28 , I, 659.

[72] See above, chapter 28 , I, 657.

[73] See above,