many said, than the peace of Aix-la-Chapelle. Through the observations thus made errors were corrected and an impulse given to the study of astronomy which accounts in great part for the progress it made during the last half of the century.
Prior to the middle of the century little progress had been made in many of the sciences which in the next century engaged the attention of its foremost men. Sauvier had distinguished seven laws of sound and interested a good many men in their study. But at the beginning of the century the subject of acoustics was little understood and progress in its development was slow. Considerable attention was given to the subject of electricity, but neither Buffon nor D'Alembert believed that the calculus could be employed in this branch of science as it had been in setting forth the principles of astronomy and optics. A generation later than Buffon it was found that the calculus was of inestimable value in the study of every branch of science. Increase in the knowledge of chemistry was due quite as much to the pharmacists as to its special representatives in the academy. The contributions of one of these pharmacists, Etienne Geoffroy, in his tables of "Chemical Affinities" were of great value. Yet he did not realize, as Newton had done, the importance of his discoveries. As long as the influence of Descartes continued dominant in the academy, progress was difficult, Cartesians were content to explain the reciprocal action of molecules by mechanical forces. Such men as Nicolas Lemery and Fontenelle could see nothing but originality and useless knowledge in the discoveries of Geoff roy. They were unwilling to accept Newton's theory of gravitation. It was a long time before the principles accepted in England, or in Germany under the leadership of Stahl, in chemistry, prevailed in France. Up to the year 1780 the science of mineralogy in France was in a state of torpor. At that time the science of crystallography, and of geology, was unknown. Some progress had been made in the study of botany. As early as 1746 Guellard tried to persuade the academy to give its attention to the study of flora and fauna. The establishment of the Royal Gardens, chiefly for the benefit of medical science, had rendered the study of botany possible and attractive. In 1700 Tournefort, who had been at the head of the gardens since 1683, published his very important "Institutio rei herbariæ." His classification was based on color rather than on structure or function. The relation between descriptive and vegetable physiology was then unknown and was made of no practical value till a century later. Yet Tournefort recognized the existence of genera if not of species. In 1727 the existence of sex in plants was discovered. Not long after Tournefort's death Linnaeus visited France, where he was warmly received and urged to remain as a member of the academy. Though refusing to leave Sweden permanently, he interested members of the academy in his theories and methods of classification which were at once seen to be an immense improvement