CONTENTS. 
XXXIX 
PACK 
Macloskie, G . — The Dioptrical Principles of the Microscope (Fig. 21) .. Parti 135 
Ewell, M. D. — The Effect of Curvature of the Cover-glass upon Micrometry „ 137 
Nelson, E. M . — Simple Method of Finding the Refractive Index of various 
Mounting Media „ 141 
„ „ Virtual Images and Initial Magnifying Power .. .. Part 2 180,302 
Jameson, H. G . — Microscope Tube-length and Resolving Power Part 2 272 
Castellarnau, D. Joaquin Ma. de— Optical Theory of the Microscope. 
The Virtual Image ,, 273 
Czapski, S . — Calculable Limit of Microscopic Vision „ 302 
Nelson, E. M . — Penetrating Power of the Microscope Part 3 331, 448 
Abbe — Determination of the Focal Length of Optical Systems Part 3 427 
Abbe & Czapski — Microscopic Image of Transparent Bodies „ 427 
Sang — Investigation of the Action of Nicol’s Polarizing Eye-piece .. . . „ 428 
Nelson, E. M . — Rings and Brushes seen with the Polariscope „ 448 
Czapski, S. — Abbe’s Method axd Apparatus for the Determination of Focal 
Lengths (Figs. 76-80) Part 5 678 
„ „ The Dioptric Conditions for the Measurement of Optic Axial 
Angles by means of the Polarization Microscope „ 683 
D’Ogagne — Geometrical Representation of the Formula for Lenses .. .. „ 683 
Nelson, E. M . — Rings and Brushes (Fig. 81) „ 683 
„ „ Simple Method of Finding the Refractive Index of various 
Mounting Media Part 6 875 
Pulfrich, C. — Abbe Measuring Apparatus for Physicists (Figs. 100-102).. „ 876 
(6) Miscellaneous. 
Zoth, O . — Experiments on the Diffracting Structure of Striated Muscle-fibre 
(Figs. 22-24) 
The Late Mr. G. F. Dowdeswell, F.R.M.S. 
Good Advice I 
Exhibition of Microscopes at Antwerp in 1891 
Smith, A. Hopewell — Simple Method of Drawing Microscopical Prepara- 
tions 
Tolman, H. L. — Walter E. Bulloch 
Dr. Van Heurck on the Microscope 
Gage’s (S. H.) Text-book of the Microscope 
Behrens’ Tables for Microscopists 
Jackson, H. — Nature of Solutions and the Use of the Microscope 
The Late Mr. W. W. Reeves 
Ink jor Writing on Glass or Porcelain 
Weight, L., S. Czapski, & R. Kanthack — Spherical Aberration — Apochro- 
matic Objectives 
Ward, R. H . — Microscopes and Accessories at the Antwerp Microscopical 
Exhibition 
Bonnet, T. G. — The Microscope’s Contributions to the Earth’s Physical 
History 
“ The Times ” — The Microscope as an Aid to Physiology 
Taylor, T. — Twentieth Annual Report of Chief of the Division of Micros- 
copy, U.S.A 
Part 1 142 
„ 147 
„ 147 
Part 2 273 
„ 277 
„ 278 
Part 3 428 
„ 430 
431 
„ 431 
„ 431 
Part 4 552 
„ £52 
Part 5 684 
„ 688 
Part 6 881 
„ 881 
0. Technique. 
Zimmermann’s Botanical Micro-technique Part 4 555 
Klein, L . — Microtechnique of Vegetable Objects Part 5 689 
