698 SUMMARY OF CURRENT RESEARCHES RELATING TO 



tatice between a division ou the scale and its reflected image. If, e.g., the 

 distance between 771 mm. and its image measured in fractions of one of 

 the visible intervals is 1*4 mm., then the true reading is 771*7 mm. 

 A great advantage of the method is that it obviates all catlictometer 

 adjustments and errors. The errors introduced by refraction through 

 parts of the glass tube, while not entirely eliminated, are less pronounced 

 than in other methods.] 



Zeitschr. f. Instrumentenk., VI. (1886) pp. 89-93 (4 figs.). 



Thompson, G.— The determination of the Index of Refraction of a fluid by 



means of the Microscope. Nature, XXXIV. (1886) pp. 157 and 217. 



Also criticisms by J. II. Gladstone and L. Bleekrode, pp. 192 and 290. 



Thompson, S. P. — Notes on some new Polarizing Prisms. 



[1. Ahrens', ante, p. 397. 2. Simple modification of the Nicol prism, 

 giving wider angle of field. PostJ] 



Phil. Mag., 188G, pp. 47G-80 (1 pi.). 

 To i son, J. — Eclairage intensif en micrographie. (Condensed illumination in 

 microscopy.) 



[Suggests as a substitute for the Abbe condenser an objective — 1/7 in. 

 0"94 N.A. — fixed in the cylinder diaphragm-holder.] 



Juurn. Sci. Med. Lille, 1885, 5 pp. 

 Wallace, K., Jun.— The Amateur Photographer: A Manual of Photographic 

 Manipulation, intended especially for Beginners and Amateurs. 



205 pp., 1 phot., and figs. (8vo, Philadelphia). 

 Waterhouse, A. — Blood Measurements. 



[Table of measurements of blood-corpuscles of various species of Mammals]. 



The Microscope, VI. (1886) pp. 97-101. 

 Weyers, J. L. — Le Microscope Entomologique. (The Entomological Micro- 

 scope.) CP. Soc. Entomol. Belg., 1S86, No. 71, pp. xc.-xciii. 



B- Collecting', Mounting and Examining Objects, &c* 



Histophysics of the Red Blood-corpuscles.t— Drs. S. J. Meltzer 

 and W. H. Welch have had occasion in the course of their investiga- 

 tion on the colouring matter of the blood, to search for the remains 

 of the uncoloured red blood-cells, the so-called phantoms. Their 

 experience was that these can be rendered more evident by means of 

 certain substances capable of coagulating albumen, such as prussic 

 acid (saturated solution), pyrogallic acid (20 per cent.), copper sul- 

 phate (10 per cent.), chlorate of potash (6 per cent.), silver nitrate 

 (3 per cent.). The phantom corpuscles appear as dark rings ; on the 

 application of chlorate of potash as pale bluish discs. The last three 

 reagents have the advantage of not altering blood-corpuscles present 

 with the phantoms. 



Counting Blood-corpuscles.| — For counting white blood-cor- 

 puscles M. J. Toison adopted the staining method, using the basic 

 anilins, of which he found methyl-violet 5 B the most reliable. 



The formula given is : — Distilled water, 160 c.cm. ; glycerin at 



* This subdivision contains (1) Collecting Objects ; (2) Preparing, (a) in 

 general, (6) special objects ; (3) Separate processes prior to making sections ; 

 (4) Cutting, including Imbedding and Microtomes; (5) Staining and Injecting ; 

 (6) Mounting, including preservative fluids, cells, slides, and cabinets ; (7) Ex- 

 amining objects, including Testing ; (8) Miscellaneous matters. 



f Centralbl. f. d. Med. Wiss., 1884, p. 721. 



j Journ. Sci. Med. de Lille, 1885, 4 pp. 



