THE MICROSCOPE. 147 



Newton makes no original investigations in this direction, but 

 suggests the most probable explanation of the facts discovered. 



Beccaria and Martin added some to the already made observa- 

 tions. 



After the construction of the reflecting telescope, it was natural 

 to apply the same principles to the microscope. This was done by 

 Dr. Robt. Barker' and Dr. Smith. '^ Neither of these constructions 

 became popular, owing to expense and difificulty of manipulation. 



About this time, /. c. 1738-39, Lieberkuhn produced his solar 

 microscope, and reproduced the opaque illuminator of Leuwen- 

 hoek, to condense and render more uniform the light as reflected 

 from mirror. His objects were all the most "curious anatomical 

 preparations," some of which, with the microscope, can now be seen 

 in the British Museum. When in England, in 1739, he showed 

 these instruments made by himself to several gentlemen, among 

 whom was the optician, Mr. Cuff, who thereafter made solar micro- 

 scopes after this design. These inventions, together with Trem- 

 bley's discovery of the polyp, gave a new impetus to this almost 

 dead science. As made by Cuff, they consisted of a Wilson's pocket 

 microscope plus a large tube, condensing lens and mirror. The 

 tube was intended to adapt to hole in shutter. The mirror, regu- 

 lated by jointed wires, reflected the rays through the condensing 

 lens into the tube and thence through the microscope attached to 

 the end of tube. This same crude arrangement was brought out 

 in Chicago a few years since as " Mcintosh's solar microscope." 

 The concave reflector known now as "Lieberkuhn" we are all so 

 well acquainted with as to render description and remarks unneces- 

 sary. 



Every optician now bent himself to "improve " the microscope, 

 in other words, he strove his utmost to make it in all respects dif- 

 ferent from that of his neighbor. As a result, the instrument, 

 instead of being improved, lost many of the advantages of the older 

 forms. At this same period, M. Buffou's famous system of organic 

 molecules was given to the world, as well as Needham's theory of 

 vegetable force and the vitality of matter — both came from the 

 microscope. 



I Phil. Trans., Vol. 8, part i, p. lao. 

 a Smith's Optics, p. 94. 



