The diffusion of alchemy westward, like the movement of astrology eastward, became significant only in the centuries after 200 A.D. The conservatism of learning was such that, even when commercial intercourse had made intellectual contacts possible, little serious interchange took place until severe social stress had disturbed the even tenor of the times in China, India, and Europe. Technology was a little, but only a little, less conservative.
William H. McNeill