's Laws of Thought, and
on the formation of a Chinese dictionary.

[114] Douglas Derion Heath (1811-1897), a classical and mathematical
scholar.

[115] There have been numerous editions of Bacon's complete works,
including the following: Frankfort, 1665; London, 1730, 1740, 1764, 1765,
1778, 1803, 1807, 1818, 1819, 1824, 1825-36, 1857-74, 1877. The edition to
which De Morgan refers is that of 1857-74, 14 vols., of which five were
apparently out at the time he wrote. There were also French editions in
1800 and 1835.

[116] So in the original for Tycho Brahe.

[117] In general these men acted before Baron wrote, or at any rate, before
he wrote the _Novum Organum_, but the statement must not be taken too
literally. The dates are as follows: Copernicus, 1473-1543; Tycho Brahe,
1546-1601; Gilbert, 1540-1603; Kepler, 1571-1630; Galileo, 1564-1642;
Harvey, 1578-1657. For example, Harvey's _Exercitatio Anatomica de Motu
Cordis et Sanguinis_ did not appear until 1628, and his _Exercitationes de
Generatione_ until 1651.

[118] Robert Hooke (1635-1703) studied under Robert Boyle at Oxford. He was
"Curator of Experiments" to the Royal Society and its secretary, and was
professor of geometry at Gresham College, London. It is true that he was
"very little of a mathematician" although he wrote on the motion of the
earth (1674), on helioscopes and other instruments (1675), on the rotation
of Jupiter (1666), and on barometers and sails.

[119] The son of the Sir William mentioned below. He was born in 1792 and
died in 1871. He wrote a treatise on light (1831) and one on astronomy
(1836), and established an observatory at the Cape of Good Hope where he
made observations during 1834-1838, publishing them in 1847. On his return
to England he was knighted, and in 1848 was made president of the Royal
Society. The title of the work to which reference is made is: _A
preliminary discourse on the Study of Natural Philosophy_. It appeared at
London in 1831.

[120] Sir William was horn at Hanover in 1738 and died at Slough, near
Windsor in 1822. He discovered the planet Uranus and six satellites,
besides two satellites of Saturn. He was knighted by George III.

[121] This was the work of 1836. He also published a work entitled
_Outlines of Astronomy_ in 1849.

[122] While Newton does not tell the story, he refers in the _Principia_
(1714 edition, p. 293) to the accident caused by his cat.

[123] Marino Ghetaldi (1566-1627), whose _Prom