318 Transactions of the Society. 



of convex spectacles is attributed to Salvino d'Amartn degli 

 Arrnati, of Florence, and to Alessandro de Spina, of Pisa, aboul 

 the year 1300, and these aids to vision were familiar to many 

 throughout the fourteenth, fifteenth and sixteenth centuries.* 

 During this period the optical properties of lenses were investi- 

 gated by the penetrating genius of Leonardo da Vinci (1 452-1519),f 

 and by the mathematical skill of Maurolico (1494-1575)4 while 

 convex spectacles must have been on the nose of many a careful 

 illuminator of manuscripts. It is yet an extraordinary fact, and 

 one which requires further explanation, that there is no single 

 instance on record of these glasses having been used for the in- 

 vestigation of nature. Many illuminated manuscripts of the 

 fifteenth and sixteenth centuries, especially those of the Flemish 

 school, betray the most exquisite care in draughtsmanship ; notably, 

 the marginal decorations ol'ten involve figures of insects and flowers 

 showing the greatest skill in portrayal. Yet these figures never 



suggest the use of a magnifying glass to 

 reveal any detail of the object drawn, while 

 it is often hard not to believe that such an 

 aid to vision must have been used in 

 guiding the minutely accurate movements 

 of the artist's pen or brush. 



The first illustrated, publication for 

 whi h there is evidence of the use of a 

 magnifying glass appeared in the year 

 1592, at Frankfort, bearing the name of 

 George Hcefnagel (1545-1600).§ The 

 IG of 8 ^ E a n s a c& fi n gU b r ; volume consists merely of a series of 

 Hcefnagel, 1592. plates engraved on copper, illustrating 



* On the subject of the invention of spectacles see Horner, " Ueber Brillen aus 

 alter und neuer Zeit," 1885; P. Pansier, " Histoire des Lunettes," Paris, 1901 ; 

 E. Bock, "Die Brille und ihre Geschichte," Vienna, 1903; Du Bois-Raymond, 

 " Zur Geschichte der Glass Linsen," 1905; Hirschberg, in "Geschichte der 

 Augenheilkunde," Leipz., 1906 : Buch 11, Teil 2 ; B. Laufer, in " Mitteilungen zur 

 Geschichte der Medizin und Naturwissenschaften, 1907, vi. p. 379; E. H. Oppen- 

 heimer, " Der Erfindung der Brille," in Zentralzeit, f. Optik u. Mechanik, 1908, 

 p. 13 ; R. Greef, " Die altesten uns erhaltenen Brillen," in Arch. f. Opthal. Wiesb., 

 1912, lxxii., pp. 44-51. The role of Salvino d'Amarto and Alessandro de Spina has 

 been recently re-discussed by Vincenzo Rocchi, "Appunti di Storia Critics del 

 Microscopio," in the Rivista di Storia Critica delle Scienze Mediche e Naturali, 

 January, 1913, anno iv., No. 1, p. 4 ff, and by G. H. Oliver, in the Brit. Med. 

 Journ. 1913. It has been alleged that in the thirteenth century, and even earlier, 

 spectacles were in use among the Chinese. On this point see Hirschberg in 

 " Mitteilungen zur Geschichte der Medizin," 1907, vi. p. 550. 



t On Leonardo's knowledge of optics see Otto Werner, " Zur Physik da 

 Vincis," Berlin, 1911, p. 142. 



X Francesco Maurolico, " Photismi de lumine et umbra ad perspectivam 

 radiorium incidentium facientes," Venice, 1575. 



§ The title-page is worded as follows: " Archetypa studisque patris Georgii 

 Hoefnagelii. Jacobus F. genio duce ab ipso scalpta, omnibus philomusis amice 

 D ; ac perbenigne communicat, Ann, Sal ; xcii. Aetat xvn. Frankfort a/M." 



