SIR ROBERT HADFIELD, BART. 11 



the perfect gem cutting of the Ancients could not have been attained 

 without the use of magnifiers. 



In the Book " Essays on the Microscope " by George Adams, 

 Mathematical Instrument Maker to His Majesty (1787), being " A 

 Practical Description of the Most Improved Microscopes," which was 

 one of the Standard Works at that time, Adams said : " It is generally 

 supposed that Microscopes were invented about the year 1580, a 

 period fruitful in discoveries. The honour of the Invention is claimed 

 by the Italians and the Dutch ; the name of the Inventor appears, 

 however, lost." 



With regard to the many interesting facts relating to the early 

 History of the Microscope, two valuable contributions have been made 

 by Dr. Charles Singer, M.D., " Notes on the Early History of the 

 Microscope " read before the Royal Society of Medicine in 1914, and 

 " The Dawn of Microscopical Discovery," before the Royal Micro- 

 scopical Society in 1915. 



In giving the following information I have taken the liberty of 

 freely making use of the valuable Researches of Dr. Singer, who points 

 out that there have been three main epochs in the History of Micro- 

 scopical Discovery. There was the Pioneer Period, extending to 

 about 1660, the Classical Period, covering half-a-century or more from 

 about 1660, and including the work of the great Microscopists, Hooke, 

 Grew, Malpighi, Leeuwenhoek and Swammerdam, and finally the 

 Modern Period, dating from the Optical Discoveries of Newton. 



The earliest microscopical observation known is stated by Dr. 

 Singer to be of Seneca (circa A.D. 63) who in his " Quaestiones Natur- 

 ales " said that " Letters, however small and dim, are comparatively 

 large and distinct when seen through a glass globe filled with water." 



The properties of curved reflecting surfaces, and even to some 

 extent of Lenses, were known to the ancients, and to some mediaeval 

 writers, such as Roger Bacon. The invention of convex spectacles 

 is attributed to Salvino d'Amarto degli Armata, of Florence, and to 

 Alessandro de Spina, of Pisa, about 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 investigated by the penetrating genius of Leonardo da 

 Vinci (1452-1519) and by the mathematical skill of Maurolico (1494- 

 1575). while convex spectacles must have been on the nose of many a 

 careful illuminator of manuscripts. 



Up to this time Dr. Singer points out there is no single instance 

 on record of these glasses having been used for the investigation of 

 nature and that even the many illuminated manuscripts of the fifteenth 

 and sixteenth centuries, especially of the Flemish school, do not suggest 

 the use of magnifying glasses. 



The first illustrated publication, for which there is evidence of the 

 use of a magnifying glass, appeared in the year 1592 at Frankfort, 

 bearing the name of George Hoefnagel (1545-1600). The volume 

 consisted of a series of plates engraved on copper, illustrating common 

 objects of nature, but drawn with exceptional skill and minute accuracy. 

 Some few of these drawings revealed enlarged details which would 



