It is not probable that the Aryan invaders waged exterminating war against the Neolithic tribes. The evidence shows that there was considerable mingling of the two races. It has been suggested, however, that the Neolithic people who were not driven away were reduced to slavery.4 However that may be, the remains of the two people are found side by side in chambered tombs and sepulchral caverns, showing that they dwelt together in the same area. As before remarked, the Aryan invaders are identified as the Celts. That it was relatively late in the Neolithic Age when they made their appearance, is shown by the fact that they had only reached the English Channel when a knowledge of bronze caught up with them.
We must now endeavor to learn the origin of bronze. The impulsive energies of this newer race found vent not only in conquest over the neighboring tribes, but it is extremely probable that they are the ones who first compelled nature to yield up her metallic stores to be of service to man. If the knowledge of fire was the starting point of human advancement, surely the knowledge of metals, their useful properties, and how to extract them from their ores, may lay claim to being the starting point of our present enlightenment. We have but to glance around us to see how many of our daily comforts are dependent on the use of metals. Should we, by any mischance, become deprived of the use of iron, or of the useful alloys, bronze and brass, our civilization would be in great danger of reverting to Savagism. Man, destitute of metals, can do but little to improve his surroundings; but grant him these, and victory over his environment is secured.
We can not retrace the exact steps of this beautiful discovery; we are not sure to what family it is to be ascribed. Perhaps not to any one alone. Nature may have taken her children by the hand, and kindly guided their feeble steps in the line of experiments leading up to this knowledge, and, finally, one family, more fortunate than the others, succeeded in the attempt. All great discoveries have been approached in different directions, by different people. No sooner is it made than this fact appears, and people widely separated by time and place are found to be on the verge of the same great truth. It was probably so at the discovery of metallurgy.