CELEBRATION ADDRESSES 57 



ROYAL ACADEMY OF SCIENCES, AMSTERDAM 



THE ROYAL ACADEMY OF SCIENCES OF AMSTERDAM offers its best con- 

 gratulations to the Royal Society of London on the occasion of the cele- 

 bration of its two hundred and fiftieth anniversary. In these two hundred 

 and fifty years Science has reached a high degree of development, to which 

 the Royal Society, as one of the earliest scientific institutions, has powerfully 

 contributed. The Royal Academy of Sciences remembers with pleasure the 

 feelings of friendship which have always existed between the Royal Society 

 and Dutch scholars throughout the period of its existence. For ever memo- 

 rable, not only to the Academy, but also to the whole of the Dutch nation, 

 will be the encouragement which the Royal Society shortly after its founda- 

 tion gave to Leeuwenhoek by appointing him a Fellow of the Society in 1679, 

 a distinction highly valued by him, and which has undoubtedly been pro- 

 motive both to the production and to the spread of his inventions, which he 

 communicated in a correspondence with the Royal Society extending over 

 forty-four years. Further the Academy recalls on this occasion with great 

 acknowledgement, how Christian Huygens, the contemporary and corre- 

 spondent of Newton, Flamsteed, Boyle, Locke, with which famous men he was 

 personally acquainted, was one of the first foreign members of the Royal 

 Society. And how on Boerhaave, also a Fellow of the Royal Society, the 

 special honour was conferred that Cromwell Mortimer, then Secretary of the 

 Royal Society, dedicated the thirty-ninth volume of the Philosophical 

 Transactions to this scholar in 1735. The Royal Academy of Sciences 

 wishes the Royal Society many years of great prosperity, and expresses the 

 hope that the mutual feelings of friendship, which have been entertained for 

 two and a half centuries, may continue to exist in the future. 

 Amsterdam, July 1912. 



P. D. CHANTEPIE DE LA SAUSSAYE, President. 

 P. ZEEMAN, Secretary. 



DUTCH SOCIETY OF SCIENCES, HAARLEM 



THE PRESIDENT AND COUNCIL OF THE DUTCH SOCIETY OF SCIENCES offer their 

 most sincere congratulations to the Royal Society on the occasion of its 

 250th anniversary. Few Societies can look back on an uninterrupted existence 

 of two and a half centuries, less on a continuous activity during so long 

 a time and none on a higher class of scientific work than that published 

 by the Royal Society. The President and Council of the Dutch Society of 

 Sciences can therefore frame no better wish, than that the Royal Society may 

 for many more centuries continue to promote knowledge and consequently 

 human happiness in the same admirable way as heretofore. For the Presi- 

 dent and Council of the Dutch Society of Sciences, 



Haarlem, July 12th, 1912. LOTSY, perpetual Secretary. 



