( 10 ) 
Illustrated by Fifty-three Plates and more than Eight Hundred|Woodcuts, giving 
figures of nearly 3000 Microscopic Objects. 8vo. Cloth. £2 12s. 6d. 
Griffith & Henfrey’s Micrographic Dictionary: 
A Guide to the Examination and Investigation of the Structure 
and Nature of Microscopic Orjects. 
FOURTH EDITION. 
Edited by J. W. GRIFFITH, M.D., &c„ assisted by The Rev. M. J. BERKELEY, 
M.A., F.L.S., and T. RUPERT JONES, F.R.S., F.G.S., &c. 
“ A valuable handbook even for the advanced student of nature, to whom, moreover, the having such a 
vast mass of scattered zoological and botanical knowledge brought together within the compass of a single 
volume cannot but be exceedingly convenient .” — Annals of Natural History. 
LONDON : GURNEY & JACKSON, 1, PATERNOSTER ROW. 
(Successors to Mr. VAN VOORST.) 
SWIFT & SON’S New 1/12 in. Homogeneous Immersion Objective of 
^1*25 N.A., in which the New Abbe-Schott glass is used, price £5 5s. 
This lens Swift & Son guarantee to be equal to any other Homogeneous Immersion 
Objective of the same N.A. 
Swift & Son are continually receiving testimonials in praise of the above Objective. 
A New 1/12 in. Apochromatic Homogeneous Immersion Objective of 
1-4 N.A, £16. 
Compensating Eye-pieces, magnifying 10, 20, and 30 times, price 
each, £2. 
These Eye-pieces also give excellent results with Objectives made with the old Media. 
Projection Eye-pieces for Photo-Micrography, magnifying 3 and 
6 times, each £2. 
For particulars of Professor Crookshank’s Bacteriological Microscope, and Medical 
Press Comments, send for Circular. 
UNIYERSITY OPTICAL WORKS, 
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ROYAL MICROSCOPICAL SOCIETY. 
MEETINGS FOE 1891, at 8 p.m. 
Wednesday, January . . . . 21 
{Annual Meeting for Election of 
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