[298] Opt. Book II. par. 3. prop. 4.

[299] Opt. Book II. pag. 241.

[300] Ibid. pag. 224.

[301] Ibid. Obs. 17. &c.

[302] Ibid. Obs. 10.

[303] Ibid. pag. 206.

[304] Obser. 21.

[305] Observ. 5. compared with Observ. 10

[306] Ibid. prop. 5.

[307] Observ. 7.