G(M SEC. 18. BIOLOGY. 



Though effecting one object well it has given way to more complicated 

 motions adapted to many uses. 



3519. Old-fashioned Solar Microscope ; date about 

 1800. Essex and C helms ford Museum. 



Presented to the Museum by the late J. Disney, Esq., F.R.S., about 50 

 years ago. 



3526. Achromatic Microscope, made in 1807 by Hermann 

 van Devi, in Holland, the first maker of true achromatic objective 

 lenses for microscopes. 



Prof. Buys-Ballot, Utrecht, Holland. 



(See Hurting, Das Mikroskop, iii., page 132, sqq., where this very micro- 

 scope is described.) 



3513. Wilson's Pocket Microscope, with three single 

 powers, about \, ^, and J inch, and box of objects of an early 

 period. William Sykes Ward. 



3514. Pocket Microscope, for opaque objects, four powers 

 in Lieberkuhns 1 in.. 1 in., J in., and - in. William Sykes Ward. 



3515. Achromatic Microscope, by Oberhiiuser, of Paris, 

 with powers of an early period; fine adjustment, achromatic con- 

 denser, and a curious double movement stage. 



William Sykcs Ward. 



3516. Compound Microscope, by Dollond, formerly be- 

 longing to Josiah Wedgwood, potter. It is not inclinable ; 

 provided with two movements ; the stage is rude in mechanism. 

 There are six object-glasses, frog-plate, and other appliances. 



Robert Garner, F.R.C.S. 



3520. Microscope used by Sir W. Hooker, and em- 

 ployed by him in describing the British Jungermanma?, Musci 

 exotici, &c. J. D. Hooker, M.D., P.R.S. 



3521. Microscope -used by Daws on Turner, and em- 

 ployed by him in describing the " Alga3 " for the " Historia 

 Fucorum." J. D. Hooker, M.D., P.R.S. 



3522. Microscope which belonged to Kobert Brown, and 



WHS employed by him in his various botanical researches. 



J. D. Hooker, M.D., P.R.S. 



3523. Copy of Microscope used by Louis Claude Marie 

 Richard in the Analyse du fruit, made for Robert Brown. 



J. D. Hooker, M.D., P.R.S. 



3524. Large Microscope, made by S. Ploessl, of Vienna, 

 in 1845. With screw micrometer and other accessory apparatus. 

 (Property of Prof. F. Cohn.) 



Prof. Ferd. Cohn, of the Institute of Vegetable Physiology 

 in the University of Breslau. 



