A58 Natural-Historical Collections. 
century, that the change took place. Thus the sciences are in reality only founded 
on three centuries of well regulated labours. 
Having thus marked the character of the three scientific epochs, the Professor 
returned to the first ; and, with the view of determining its origin, he penetrated 
the antiquity of human society: he showed that, notwithstanding the inconsi- 
derable data which we possess on this subject, it is possible to obtain some satis- 
factory results, by relying at once on history and geology, whose evidences are 
mutually confirmative. Thus, whilst the traditions of all nations have preserved 
the remembrance of one great catastrophe, which changed the surface of the 
earth, and almost annihilated the human race, geology teaches us, that, of the 
different revolutions which have agitated our globe, the last corresponds, evi- 
dently, with the epoch which we assign to the deluge. 
We will tell you, said he, how, by means of considerations purely geological, 
we can obtain, with a degree of precision, the date of this great event. 
There are certain formations which must have been commenced immediately 
after the last catastrophe, and which, from that moment, have been continued to our 
days with marked regularity. Such are the deposits which we observe at the 
mouths of rivers, the detritus which lies at the foot of mountains, and is formed of 
the debris which falls from the summit. These deposits increase every year, by 
a quantity which observation can make known te us. Consequently, nothing is 
more easy than to calculate the time which would have been required to produce 
the accumulation which we see at this day. This calculation has been made for 
the detritus of mountains ; and we have found it to be, in every instance, from 5 
to 6000 years. It has been made for the deposits of rivers, and has given the same 
number of years. In fine, whatever natural phenomenon has been interrogated, 
we have always received a confirmation of the exaetitude of the traditions. These 
traditions themselves, treasured in the recollection of men, present the most as- 
tonishing conformity. The Hebrew text of Genesis places the deluge in the year 
2349, before Christ. The Indians make the fourth age of the world—the age in 
which we live—to commence in 3012. The Chinese date it about 2384. Con- 
fucius indeed represents the first king, Yao, as being occupied in draining off 
the waters of the ocean, which were elevated to the tops of the mountains, and 
in repairing the injuries which they had caused. 
It was certainly long posterior to this epoch that men began to cultivate the 
sciences. Astronomy presents the earliest traces, and seems to have sprung 
up simultaneously in many countries. ‘The first observation of an eclipse 
made by the Chinese, and of established authenticity, was in the year 776. 
At Babylon, the most ancient observation made by the Chaldeans, was in the 
year 747. There is a statement, it is true, that Callysthenes brought from 
Babylon to Aristotle a series of observations which comprized a period of 1900 
years; but this assertion, which was found for the first time in Synesius, a writer 
of the 16th century, deserves no confidence. Aristotle, who speaks of astronomy 
in many parts of his works, would not have omitted to notice a fact so important. 
It has been supposed that we had discovered in the zodiacs traced on the walls 
of certain temples in Egypt, a proof that astronomy was cultivated in that coun- 
try from the remotest times. But whatever interpretation may be given to these 
zodiacs, we now know, thanks to the discoveries of M. Champollion, the 
true antiquity of the temples. That of Denderah, in particular, was built 
under Tiberius, and bears the name of Nero: another is of the reign of Do- 
mitian. It may, then, be regarded as sufficiently proved, that the sciences only 
acquired a certain degree of perfection in the 8th century before the Christian era. 
However, many ages before that period, great nations were formed in many parts 
of the earth. About 1506 years before Christ, we find four,—_the Indians, the 
Chinese, the Babylonians, and the Egyptians. 
The Chinese having preserved a constant isolation, the progress which they 
have made has been useful only to themselves, and has contributed nothing to the 
general civilization. Thus, in giving a history of the sciences, we cannot take 
this people into account. As to the three others, we observe such a resemblahce 
