318 LEEUWENHOEK AND HIS “LITTLE ANIMALS ”’ 
The only other descriptions of the Royal Society’s micro- 
scopes were given some years later by Henry Baker‘ (1740,° 
1753), who determined their magnifying powers and—in his 
second publication—also gave two diagrammatic representa- 
tions of the instruments. Baker tells us that Leeuwenhoek’s 
microscopes were under his examination for three months,’ 
but he found Folkes had already given “ such an exact and 
full Description of their Structure and Uses, as renders any 
farther Attempt to that Purpose intirely needless.” * He 
notes that most of the objects before the glasses were even 
then (1740) “destroyed by Time, or struck off by Accident ; 
which indeed is no Wonder, as they were only glewed on a 
Pin’s Point, and left quite unguarded. Nine or Ten of them, 
however, are still remaining ; which after cleaning the Glasses, 
appeared extremely plain and distinct, and proved the great 
skill of Mr. Leeuwenhoek...’ He then makes the inter- 
esting further remark that Leeuwenhoek’s skill was also 
shown ‘in the Contrivance of the Apertures of his Glasses, 
which, when the Object was transparent, he made exceeding 
small, since much Light in that Case would be prejudicial ; 
But, when the Object itself was dark, he inlarged the Aperture, 
to give it all possible Advantage of the Light.” ’ 
But we are chiefly indebted to this verbose amateur for 
having carefully determined the focal length and magnifying 
power of every lens in the collection—notwithstanding he 
1 Henry Baker (1698-1774) was a Londoner, whose varied activities 
included dabbling in science. As a boy he was apprenticed to a bookseller, 
but later he made a fortune by teaching deaf mutes by a secret method of 
his own. In 1729 he married the youngest daughter of Daniel Defoe. He 
was elected F.R.S. in 1741, and by his will endowed the ‘ Bakerian Lecture ”’ 
of the Society. In early life he wrote much poetry and light literature. His 
chief contributions to science were two popular books on the microscope— 
mainly compilations, containing little original. In these works, which ran 
through many editions and were translated into several languages, he drew 
largely on L.’s letters. Cf. Dict. Nat. Biogr. and Rec. Roy. Soc. 
2 Though dated 1740, this paper must have been published considerably 
later: for it contains a reference to the 2nd edition of Baker’s Microscope 
Made Easy (1743: 1st ed. 1742), and he styles himself F.R.S.—to which he 
was not elected until 12 March 1741. 
* Baker (1753), p. 434 footnote. 
* Baker (1740), p. 504. 
° Baker (1740), p. 504. 
