The numerous peoples of India have always been divided into castes. This has resulted in the pioneering work in science falling to the priests. However, the principal priests were among the most intellectual men of each generation and, as they traveled in search of instruction, India was always in contact with the progress made in China, central Asia, and Babylonia. These great centers of ancient learning progressed together. The Indians were able mathematicians and discovered and developed at an early period what is now known as "Arabic notation." In this work they were assisted by the Babylonians. The Indians, like the Chinese and Babylonians, solved problems in interest, discounts, partnership, the summation of arithmetical and geometrical series, and determined number changes in combinations and permutations with ease. They were also proficient in algebra, the extraction of the roots of numbers, various classes of equations, and the principles of trigonometry. The Chinese have always been good mathematicians. It is probably due to this fact that they have at all times been such able traders and bankers. We are not so familiar with the works of Chinese mathematicians in pre-Babylonian times as we are with the Indian; but the references of contemporary writers indicate that the Chinese scientists were as able and active as their contemporaries. We have remarked the high degree of perfection which was attained in the Babylonian era by scholars in science and mathematics. Similar perfection was attained in art, industry, law, and medicine. The wonderful law work that has come down to us under the name of the code of Hammurabi indicates not only the extensive progress which had been made in law, but incidentally through its references the progress of agriculture, industry, commerce, and business. Many references in the Hammurabic code, written about 2300 B. C., show that the medical profession had attained considerable advance in Babylon. Surgeons were daring operators. They commonly performed operations for cataract. Many of the common major operations now performed by surgeons were also done by the ancients. They were experts at setting fractured bones. The physicians made effective use of drugs. Many drugs employed to-day were known to them. The discoveries of the early oriental nations were collected and developed in Babylon. The entire fields of science, mathematics, geometry, agriculture, astronomy, philosophy, and art were focused in Babylon and handed down to the Egyptians and the Greeks. Much credit that is given to ancient Greece should be shared also by Babylon. It was from Babylon that Greece obtained the principles of its civilization, arts and sciences. Even Greek architecture and sculpture were originally derived from Babylon. CHAPTER IV EGYPTIAN SCIENCE