12 INTRODrCTORY ADDRESS: 



have been hardly distinguishable to the unaided eye. These remark 

 able figures are stated to have been the work of Hoefnagel's son, 

 Jacob (1575). 



It must be remembered, however, that the occasional use by a 

 naturalist of a simple Lens of low magnifying power could have but 

 little influence on the advance of knowledge. It was not until the 

 Classical Period with the invention of Lenses of very short focus that 

 the simple Microscope became a valuable means of Research. In the 

 Pioneer Period it was rather the discovery that Lenses could be combined 

 into the Telescoj^e and the Microscope that gave the first stimulus to 

 investigation. These compound instruments were invented about 

 the vear 1610. 



1600 TO 1700 A.D. 



The Dutchman Zacharias, " miscalled Jansen, and his son made 

 Microscopes before the year 1619. It was he who, whilst still a 

 lad, had worked with his father, who was a spectacle maker, and 

 appears to have discovered accidentally the principle of a Telescope 

 by placing two Lenses together in a tube. The invention of the 

 Microscope followed about that time, though the exact date is un- 

 known. In the year 1619, Cornelius Drebbel, of Alkomar, brought 

 a Microscope which was made by the Jansens with him into England 

 and showed it to William Boreel, who was Dutch Ambassador tc 

 France, and eventually to England. It is, however, added that 

 Drebbel's instrument was not strictly what is now meant by the 

 Microscope, but was rather a kind of Microscope-Telescope, somewhat 

 similar in principle to certain apparatus described by Mr. Aepinus 

 in a letter to the Academy of Sciences, St. Petersburg. This was 

 formed of a copper tube six feet in length and one inch in diameter. 

 On the other hand, Dr. C. Singer, in his interesting Paper on " The 

 Historical Aspect of the Microscope," does not think this was the case. 



A portrait of Jansen is given in Fig. 3. A photograph is also 

 given of Hans Lipperhey (Fig. 4), who is described as the inventor 

 of the second Microscope, Jansen being referred to as the inventor 

 of the first one, that is of the special type described probably in the 

 beginning of the Seventeenth Century. 



Dr. Hooke, the author of the famous " Micrographia " in 1665, 

 described means of utilising small drops or globules of glass in a 

 Microscope, and said that by means of this he had been able to dis- 

 tinguish the particles of bodies not only a million times smaller than 

 the visible points, but even to make these visible whereof millions of 

 millions would hardly make up the bulk of the smallest visible grain 

 of sand ; so prodigiously do these exceedingly small globules enlarge 

 our prospect into the more hidden recesses of Nature. Di Torre of 

 Naples also largely made use of these globules for his well-known 



investigations. 



As regards Hooke's Book referred to, it may be interesting to give 

 a facsimile (Fig. 5) of the title page as it appeared in 1665." Hooke 

 was a Fellow of the Royal Society, and a facsimile of his signature as it 

 appears in the famous " Roll Call of Fellows " is given at the foot of 

 the front page, in Fig. 5. 



