XX XVI CONTENTS. 



Hoss'a (A.) Centering Glass (Figs. 135 and 136) .. Part 4 681 



Amici Polarizing Apparatus {Fig. 137) „ 682 



'Wm'KEjJsiR.) Micrometer Eye-piece (Figs. 138 and 13^) „ 683 



Gill, D. — Method of Webbing the Filar Micrometer „ 684 



Schkodeb's (H.) Differential-screw Fine Adjustment (Figs. 140 and 141) ,, 685 



'DeJjICAT'e Fine Adjustment (Fig. 14:2) „ 686 



Moore, A. Y. — Mechanical Stages „ 687 



Ultzmann's (E.) Saccharometer (Fig. 143) „ 687 



'Ba:k.'ES.'s New Microscope Lamp (Fig. 14i) „ 688 



ScHEEiBEE, 0. — Examination of Graduated Circles with two and four 



Microscopes „ 688 



Lommel, E. — Measuring the Focal Length of a Lens (Fig. 145) .. .. „ 689 



„ „ Measuring Indices of Pief Taction (Fig. l^Q) ,, 689 



Lepinay, M. de — Optical method for the absolute measurement of small 



lengths ,, 690 



Dancer, J. B. — Dotted appearance on Pleurosigma angulatum .. .. „ 691 



" Central v. Oblique Light " „ 692 



Nelson, E. M. — Interpretation of the Six Spectra of Pleurosigma 



angulatum „ 694 



Henocque — Apparatus for the Examination of the Blood „ 696 



Hitchcock, R. — Microscopical Exhibitions „ 696 



S., H. G. F. — A Concentric Microscope „ 697 



'RBSOuyiNG 152,000 lines to the inch „ 697 



Cheshire, F. K. — Device for the Examination of Bacteria in Culture 



Tubes „ 734 



'jacket's (A.) Large Microscope {Fig. 157) Part 5 837 



„ „ Microscope with fixed Revolver for Objectives (Fig. 158) . . „ 839 



„ „ Photo-micrographic Microscope (Figs. 159 and 160) . . '^j 840 

 „ „ Photographic Microscope for Instantaneous Photographs 



(Figs. 161-163) „ 841 



Fvesb's (R.) Petrological Microscopes (Figs. 164:-168) „ 843 



DiETJDONNB, E. — Electro-megaloscope (Fig. 169) , 846 



C^AMEn's (C.) Movable Stage (Figs, no and ni) „ 848 



Zeiss's (C.) Apochromatic Objectives, Compensating Eye-pieces, and Pro- 

 jection Eye-pieces „ 849 



Anthont, J. — Observation of Opaque or Quasi-opaque Objects in the 



Microscope „ 857 



Flesch, M. — Examination of specimens by Coloured Light , 859 



Aheens' (0. D.) Polarizing Prism „ 859 



M.iCB.Eii-'L'ETi's Comparator (Figs. 172 and 173) „ 859 



Israel's (O.) Warming Apparatus as a substitute for the Hot Stage 



(Figs.m-ne) „ 860 



Delage's (Y.) Beversible Compressor (Figs. 177 and 17S) „ 862 



CoJ.^'s (A. a.) Self-adjusting Frog-plate (Fig. 179) „ 863 



Fleischl, E. t. — Micro-stroboscope for observing Muscle-contraction in 



Insects „ 863 



Stahel, H. — Determining the Thickness of Arterial Walls „ 864 



Nelson, E. M. — Pesolution of Diatoms whose Strise are of unequal fine- 

 ness (Fig . ISO) ... „ 864 



Pieesol, G. a., J. W. Queen, & R. Hitchcock — Actinic Contrast in 



Photo-micrography „ 865 



Alfebow, S. — New Apparatus for exact Counting of Blood-corpuscles ., „ 867 



