go intelligitur primorum corporum, una,
cum ab ignis fusione refrigescerent, altera, cum reconcrescerent
ex solutione aquarum.

[56] Redeunte mox simili causa strata subinde alia aliis
imponerentur, et facies teneri adhuc orbis saepius novata est.
Donec quiescentibus causis, atque aequilibratis, consistentior
emergeret rerum status.--For an able analysis of the views of
Leibnitz, in his Protogoea, see Mr. Conybeare's Report to the
Brit. Assoc. on the Progress of Geological Science, 1832.

[57] Between the year 1688 and his death, in 1703, he read
several memoirs to the Royal Society, and delivered lectures on
various subjects, relating to fossil remains and the effects of
earthquakes.

[58] Posth. Works, Lecture, Feb. 29, 1688.

[59] Posth. Works, p. 327.

[60] Posth. Works, Lecture, Feb. 15, 1688. Hooke explained with
considerable clearness the different modes wherein organic
substances may become lapidified; and, among other illustrations,
he mentions some silicified palm-wood brought from Africa, on
which M. de la Hire had read a memoir to the Royal Academy of
France (June, 1692), wherein he had pointed out, not only the
tubes running the length of the trunk, but the roots at one
extremity. De la Hire, says Hooke, also treated of certain trees
found petrified in the "river that passes by Bakan, in the
kingdom of _Ava_, and which has for the space of ten leagues the
virtue of petrifying wood." It is an interesting fact that the
silicified wood of the Irawadi should have attracted attention
more than one hundred years ago. Remarkable discoveries have been
made there in later times of fossil animals and vegetables, by
Mr. Crawfurd and Dr. Wallich.--See Geol. Trans. vol. ii. part
iii. p. 377, second series. De la Hire cites Father Duchatz, in
the second volume of "Observations made in the Indies by the
Jesuits."

[61] Posth. Works, Lecture, May 29, 1689.

[62] Posth. Works, p. 312.

[63] Posth. Works, p. 410.

[64] Ray's Physico-theological Discourses were of somewhat later
date than Hooke's great work on earthquakes. He speaks of Hooke
as one "whom for his learning and deep insight into the mysteries
of nature he deservedly honored."--_On the Delu