Page:Popular Science Monthly Volume 46.djvu/723

Rh inspect the foundations on which our present atomic theory rests, and have an opinion of his own as to its stability." Another feature of the book is that chemical symbols are not used until the need of them has been made apparent. Full and practical directions for manipulating apparatus, taking notes, etc., are given. The author is instructor in chemistry at Phillips Exeter Academy, and the book is adapted to the needs of academy students.

years ago the Bohemian chemist Boricky published a memoir which gave rise to a new branch of chemistry. This is microchemical analysis. Other investigators have contributed to its advance, and now one of them gives us a view of its present condition. Devised for the examination of minute quantities of minerals, it has been applied also to alloys, and Prof. Behrens expects it to, rival blowpipe analysis in convenience and value. The method consists in dissolving a particle of the substance to be examined, adding a minute drop of reagent to a drop of the solution, and observing the result through the microscope. Often the drop of solution is evaporated and the form and color of the crystals it deposits are observed microscopically. Something may be learned of the composition of alloys by heating polished surfaces or etching them with acid. The practical applications of all these and many other devices are described in the manual before us, and the forms of the crystals of many substances are shown in engravings.

Egyptian Book of the Dead is one of the most remarkable books in existence. Parts of it are among the oldest texts extant, some of its chapters having been inscribed in the tomb of the Queen of Mentuhotep, of the eleventh dynasty, and one of them being ascribed to the pen of the god Thoth. Very few of the Egyptian manuscripts are of earlier date. It is, further, most obscure as to its meaning. In a literal translation it is pure nonsense, and its real meaning has to be incorporated into it from the knowledge of the ancient mysteries possessed by the reader. Some of the old priests probably comprehended it; and the more advanced of the Egyptological students of the present are gradually getting glimpses of its significance. It is essentially mythological, Mr. Davis says, "and assumes the reader's thorough knowledge of the myths and legends. No one is capable of translating a single chapter of the Book of the Dead who has wrong ideas about the religion and mythology of Egypt, and is unable to understand the numerous technical and mystical expressions which everywhere occur. It is not always easy to discover what was the primitive concept attached to a particular word. The difficulty is not in literally translating the text, but in understanding the meaning which lies concealed beneath familiar words. However, the mystical nature of the text is gradually being unraveled, and, no doubt, will be ultimately understood. But we will have to make further researches into unwritten history, or perhaps have a fuller knowledge of Egyptian symbols or allegories." The text is further obscured by errors of copyists, and muddled by comments and attempts to explain the meaning which have been interpolated into it and made by subsequent copyists to run on as if they were part of the original. The purpose of the book—which is often called the Funereal Ritual—was to instruct the soul in that which would befall it after death, and to furnish prayers to protect it against dangers and assure it desired blessings. "It was given to the departed to carry with him to the grave as a passport and aid to the memory." Accordingly, more or less of it, according to the means of the deceased, was wrapped up with the mummy or inscribed on its coffin or on the walls of its tomb. About a thousand copies of it exist among the papyri of European museums, and some hundreds in Egyptian home collections. The longest copy known is the Turin hieroglyphic papyrus, containing one hundred and sixty-five chapters, which is reproduced in this volume. Yet it is not