[218] See Harris’ Essay upon Money and Coins, part. ii. [1758] p. 127.

[219] Philosophical Magazine, (1868), 4th Series, vol. xxxvi. p. 32.

[220] Proceedings of the Royal Society, 20th June, 1872, vol. xx. p. 438.

[221] Kater’s Treatise on Mechanics, Cabinet Cyclopædia, p. 154.

[222] Grant’s History of Physical Astronomy, p. 156.

[223] Clerk Maxwell’s Theory of Heat, p. 79.

[224] Treatise on Electricity and Magnetism, vol. i. p. 3.

[225] Chemistry for Students, by A. W. Williamson. Clarendon Press Series, 2nd ed. Preface p. vi.

[226] Introduction to Chemistry, p. 131.

[227] Philosophical Transactions (1859), vol. cxlix. p. 884, &c.