Vision and Definition under tlic Microscope. 161 



1909,* and the elaborate descriptions of the instruments in the 

 Society's collection contributed to our Proceedings over a long 

 period by the Curators of Instruments, Mr. Charles F. Eousselet and 

 his predecessors. Mention may also be made here of the many 

 valuable papers contributed for over eleven years to the Society's 

 Journal by Mr. E. M. Nelson. Side by side with these reconJ.s 

 may be studied the fascinating work upon " The Early Naturalists," 

 by Professor L. C. Miall, r.E.S.,t who desires us to express to the 

 Society his regret that he is unable to be present this evening, and 

 take part in our demonstration and discussion. 



But we wish to lay emphasis upon the fact that our object 

 in laying this paper before you is more far-reaching in its intent 

 than the occupation of a single meeting of the Society. Our 

 object is in the main to give a practical demonstration of the 

 desirability, nay, the necessity for the promotion and publication 

 by this Society of a comprehensive history of the Microscope from 

 the earliest times to the present day. We have no hesitation in 

 saying, and we say it without fear of contradiction, that this 

 Society is well equipped for the task, both as regards knowledge 

 and material. It is a matter of common knowledge that the 

 private collection of our some-time Secretary, Sir Frank Crisp, is 

 one of world-wide celebrity, and that many instruments of unique 

 historical interest are in the hands of other Fellows both past 

 and present. The technical skill and scientific knowledge of 

 Messrs. Nelson, Gordon, Cheshire, Eousselet, and the historical 

 researches of Dr. Charles Singer, are, we have reason to know, at 

 the service of the Society for the furtherance of the object which 

 we have in view, and with such treasures of knowledge and material 

 at our disposal there can be no doubt of the successful accomplish- 

 ment of an authoritative and definitive work. The admirable work 

 of Harting % is sealed to those who do not read Dutch with 

 ease, though it should be noted that there is a German transla- 

 tion of Harting's work, by Dr. Fk. Wilh. Theile (Braunschweig, 

 1859). The work of Landsberg § remains unfinished ; whilst those 

 of Petri II and Eocchi T[ are necessarily circumscribed by their media 

 of publication. 



The Eoyal Microscopical Society's History of the Microscope 

 is therefore a clearly-indicated necessity, and we trust that this 



* Royal Microscopical Society's Microscopes at the Frauco-British Exhibition, 

 Journ. R. Micr. Soc, 1909, pp. 651-60. 



t L. C. Miall, "The Early Naturalists, their Lives and Work : 1530-1789," 

 London, 1912. 



X p. Harting, " Het Mikroskoop, dwzelfs gebruik, geschiedenis en tegenwoordige 

 toestand," Utrecht, 1848-50, 3 vols. 



§ C. Landsberg, " Central. Zeitung fiir Optik. und Mechauik," 1890, p. 272. 



!! B. J. Petri, " Das Mikroskop," Berlin, 1896. (Introduction.) 



^ V. Rocchi, " Appunti di Storia Critica del Microscopic, " Riv. Storia Crit. d. 

 Sci. Mediche e Nat., 1913, Ann. iv. p. 1. 



