The Dawn of Modern Chemistry. Professor JOHN MAXSON STILLMAN Some Pioneers in Mosquito Sanitation and Other Mosquito Work. Dr. The Moral Development of the Chinese. Dr. FREDERIC GOODRICH HENKE 78 Water Conservation, Fisheries and Food Supply. Dr. ROBERT E. COKER 90 The Republic of Science and of Letters; Professor Onnes and the Leiden Labora- A weekly journal covering the whole field of education SCHOOL AND SOCIETY began publication on January 2, 1915, under the editorship of Dr. J. McKeen Cattell, professor of psychology in Columbia University and the Teachers College, editor of "Science," "The Popular Science Monthly" and "The American Naturalist." The journal will follow the general lines that have made "Science" of service in the sciences, cooperating with publications in special fields, aiming to become the professional journal for those engaged in the work of our lower and higher schools, and to be of interest to the wider public for whom education is of vital concern. It will emphasize the relations of education to the social order, scientific research in education and its applications, freedom of discussion, and reports and news of events of educational interest. A weekly journal of education of this character, which at present does not exist in any country, has been under consideration for some time, but the plans were postponed on the outbreak of the war. Finally, however, it appeared that if the European nations must neglect their educational interests it is all the more important that we should do the best we can in America, and the journal has begun publication at a time when there is thrust on this country great responsibility and great opportunity. The publishers hope that those who read this announcement will subscribe to the journal in order to assure its usefulness and success. There will be published two volumes a year, each containing over 800 double column pages of reading matter well printed on good paper. The annual subscription price is $3.00, the cost of a volume, $1.50, and the charge for single copies, 10 cents. LANCASTER, PA. THE SCIENCE PRESS GARRISON, N. Y. To THE SCIENCE PRESS Lancaster, Pa., and Garrison, N. Y. Please enter my name as a subscriber for School and Society, for THE POPULAR SCIENCE THE MONTHLY JULY, 1915 THE DAWN OF MODERN CHEMISTRY. BY PROFESSOR JOHN MAXSON STILLMAN STANFORD UNIVERSITY HE period of the history of chemistry which I have chosen to designate as the dawn of modern chemistry begins practically in the early sixteenth century and extends well toward the latter part of the eighteenth century. Not that the chemistry of that period shows any very clear relation to the present state of chemical science, but because at about the middle of the sixteenth century there was inaugurated an era of activity in chemical thought and experimentation, which has continued with steadily increasing velocity and productiveness to the present time. The period referred to does not by any means mark the beginnings of chemical arts or theories, for the beginnings of the technical arts of chemistry may be traced back as far as recorded history. The earliest records of Egyptian or Babylonian origin show that the arts of metallurgy, the making of bronzes and other alloys, have been practised, and uninterruptedly so, since at least some 3,500 years before the Christian era. So also the manufacture of glass and pottery, the coloring of glass and pottery, the manufacture of colors for dyeing and painting, are of great antiquity. It is worthy of note also that these technical arts of chemistry possessed since very ancient times a kind of literature of their own in the form of recipes and directions for the various processes of the special art. Such manuscripts were doubtless not meant for public information, but for the use of the artisan alone, and were transmitted from the master to the apprentice or successor for his own use. The earliest original manuscript of this character known to exist is a manuscript on papyrus written in the Greek language which was discovered in an Egyptian tomb at Thebes, and is now preserved at Leyden. It dates from the third century of our era, and was doubtless a manuscript which escaped the wholesale destruction of alchemical and magical works in A.D. 290 by order of the Emperor Diocletian, issued, as believed, to prevent the danger of the possible making of gold by the alchemists and its resulting influence upon the currency system of the Empire. This work consists of recipes for the testing of metals, their purification, their alloying, making of bronzes and brasses, the coloring of metallic objects by superficial alloying, imitations of gold, writing in gold letters, preparation of purple colors, etc. Some hundred recipes in all are contained in this manuscript. It is evidently based upon earlier works of similar character, and indeed. earlier works whose contents have been preserved to us through the mediation of copies or abstracts by later writers evidence that the ideas and methods were doubtless mostly centuries old when this papyrus manuscript of Leyden was written. The researches of scholars, notably of Berthelot, have shown how very similar, in many cases identical, recipes to those of the papyrus of Leyden have been transmitted through Roman, Arabic and later languages in manuscript form, probably uninterruptedly in Europe down to the beginning of the printing of books. It is believed that the Greeks originally derived their knowledge of the chemical arts largely from Egypt, but that the ancient Greek philosophers were the first to divorce the philosophy of chemistry from the religious ideas and magical notions of the Egyptian priesthood which with them obscured the logical reasoning from cause to effect, or from effect to cause. However that may be, the Greeks were the first sources of natural philosophy for European thought. And such names as Thales, Democritus, Pythagoras, Plato and Aristotle are names that characterize the period of the height of clarity of Greek philosophy somewhere from about 600 to 300 B.C. At about the time when this papyrus of Leyden was written the so-called Alexandrian School of Greek philosophers was dominant. This later period of Greek philosophy was marked by much brilliancy and genius, but was also characterized by a distinct influence from Egyptian sources of oriental mysticism and occult philosophy. The Romans were the natural inheritors of Greek thought, and the Roman conquest of the civilized and much of the uncivilized world again operated to spread the useful arts of chemistry as known to the ancients, though Roman influence did not contribute greatly to generalizing thought. In A.D. 489 the Alexandrian Academy was destroyed by the Emperor Zeno and its Greek scholars scattered. A body of these, mainly Syrians, established themselves in Persia, where they continued the study and teaching of the science of the Alexandrian school. Barbaric invasion resulted in almost complete extinction of the remains of Greek civilization in Europe. The Syrians in Persia were the principal conservators of ancient science, and they continued to preserve and reproduce the works of the ancient Greek writers. In the seventh century occurred the great Mohammedan conquest of the Mediterranean countries. The conquering Moslems overran |