1 68 THE POPULAR SCIENCE MONTHLY 



many said, than the peace of Aix-la-Chapelle. Through the observa- 

 tions 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 knowl- 

 edge 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 Affini- 

 ties " 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 

 Eoyal 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 herbariae." 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 



