I shall say, then, of the minimum of M. Arcelin what I have said of the maximum of M. Forel. It leaves us the certainty that the present geological period goes back much further than 7-8000 years.
VI. What corrections ought the extreme numbers which I have just quoted to undergo in order to approximate to the truth? It is still impossible to say. But the path which should be followed in order to diminish the space which separates them is henceforth clear. The alluvium of the Saône has always appeared to me to present conditions of uncertainty which it would be difficult to overcome, and the best means of determining the age of the present period by prehistoric chronology, appears to me to be the Lake of Geneva.
In order to correct the first results obtained by M. Forel, it would be necessary to take into account all the circumstances pointed out above, and several others also. It would be especially necessary, at different seasons of the year, in dry and wet weather, to gauge the smallest rivulets and ravines all round the lake, to measure the amount of mud their waters contain, and the amount of gravel and sand they carry down with it. This task is beyond the power of a single man; it would require the formation of an Association for this end. The problem would be worth the trouble, and the Swiss savants, so justly proud of their beautiful lake, might easily make arrangements to obtain its solution.
Such as they are, the works of MM. Arcelin and Forel lead to some important conclusions. The total age of our globe, used till lately to be restricted to a little more than 6,000 years; the alluvial deposits of the Saône show that the present geological epoch alone surpasses this by several centuries. On the other hand, under the influence of Darwinian prejudices, men have begun to handle time with a strange laxity, and it has been affirmed that millions of years separate us from glacial times. The deposits of silt in the Lake of Geneva show that these times terminated less than 100,000 years ago. As M. Forel well says, “This does not yet constitute historic chronology; it is, nevertheless, a little more than simple geological chronology;” and we see once more experience and observation doing justice to theoretical conceptions.
CHAPTER XIII.
AGE OF THE HUMAN SPECIES.—PAST GEOLOGICAL EPOCHS.
I. The skovmoses and the remains at Schussenried have shown that man existed in Europe at the close of the Glacial Epoch. But did he live through this epoch? Did he precede it? Has he, therefore, been contemporary with vegetable and animal species, which have long been considered as fossils? We know that we can with certainty reply in the affirmative to these questions. We know also that the proof of this great fact, one of the grandest scientific conquests of modern times, dates, so to speak, from yesterday.
This demonstration rests on proofs which are now so well known that the enumeration of them will be sufficient. It is evident that human bones, buried beneath an undisturbed layer of soil, prove the existence of man at the time when the layer was formed. It is no less clear that flints worked by human hands and made into hatchets, knives, etc., bones of animals made into harpoons and arrow-heads, are so many irrefutable testimonies of the existence of the workers. Lastly, when human bones are found associated with bones of animals in the same undisturbed layers, it is again evident that man and these animal species have been contemporaneous.
Many facts included in these three categories were proved in the earlier years, and during the course of the last century. Since 1700, excavations made by the order of Duke Eberhard Louis de Wurtemberg, at Canstadt, near Stuttgard, brought to light a great number of bones of animals, among which was found a human cranium. The nature of this precious relic was, however, only recognised by Jaeger in 1835. About the same time an Englishman, Kemp, found in London itself, side by side with the teeth of elephants, a stone hatchet similar to those of Saint Acheul. Some time after Esper in Germany, and John Frere in England, discovered more or less analogous facts. But none of them were able to recognise their significance, for geology was quite in its infancy, and palæontology not yet in existence.
II. It was not till 1823 that Amy Boué gave Cuvier some human bones which he had found in the loess of the Rhine, near Lahr, in the Duchy of Baden. Boué regarded these bones as fossils. Cuvier refused to admit this conclusion. He has often been reproached with this, but the reproach is unjust. Cuvier had too often seen pretended fossil men change either into mastodons or salamanders, or even into simple contorted blocks of sandstone, not to be on his guard, and, in presence of a fact hitherto unique, he thought it wiser to admit a disturbance which would have carried into the loess bones of much later date than that of the formation of this layer.