103G SUMMARY OF CURRENT RESEARCHES RELATING TO 



Kerber, a. — Bestimmung der Hauptbildebene und Priifixng der Korrektion- 

 zustandes optischer Systeme. (Dotcriuination of tlie principal image-plane and 

 testing of the currection-coiuiition of optical systems.) 



Ccntral-Zt;!. f. Optik u. Mcch., IX. (1888) pp. 205-8 (4 figs.). 

 Nelson, E. M. — A simple Correction for Curvature of Image. 



En.jL JilccL, XLVUI. (1888) pp. 259 (2 figs.). 



(6) Miscellaneous. 

 B., J. E. — Keview of Tripp's ' British Mosses.' 



["'Die author wisely advises her readers to avoid as much as possible the use 

 of lenses." (?)] 



Joiirn. of Bot., XXVI. ri888) p. 351. 



DoLBEAR, A. E. — The Art of Projecting ; a Manual of Experimentation in Physics, 

 Chemistry, and Natural History, with the Porte-Lumiere and Magic-Lantern. 



New ed., vi. and 178 pp., 119 figs., 8vo, Boston, 1888. 

 Fabre-Domeegue. — Premiers principes du Microscope et de la Technique Micro- 

 scopique. (First principles of the Microscope and microscopical technique.) 



250 pp. and figs., r2mo, Paris, 1888. 

 Flesch, M. — iJber den Einfluss der neueren Verbesserungen auf die Auschaffung 

 eines Mikroskopes seitens des Arztes. (On tlie influence of modern improve- 

 ments on Microscopes for medical men.) 



Corresphl. f. Schireizcr. Aerzte, XVII. (1888) p. 458. 

 L e H M A N N, O. — Molekularphysik mit besonderer Berucksichtigung mikroskopischer 

 Untersuchungen und Anleitung zu solchen, sowie einem Anhang iiber mikro- 

 skopische Analyse. (Molecular physics, with special reference to microscopical 

 investigations, and a guide thereto, as well as an appendix on microscopical 

 analysis.) 



Vol. I., X. and 852 pp., 5 pis. and 375 figs., 8vo, Leipzig, 1888. 

 Matall, J., Jun. — The Modern Microscope. I., II. 

 [Cantor Lectures at the Society of Arts, 1888.] 



Juurn. Soc. Arts, XXXVI. (1888) pp. 1149-59 (19 figs.), 1164-72 (7 figs.). 

 RoYSTON-PiGOTT, G. W. — Microscopical Advances. XXXIX., XL. 

 [Attenuated lines, circles, and dots.] 



Engl. 3Iech., XLVIII. (1888) pp. 209 and 249 (1 fig.). 



p. Technique.* 

 (1) Collectingr Objects, including: Culture Processes. 



Agar-agar for Cultivation.! — Dr. Eiclitcr gives a method for 

 making agar wliich avoids to a great extent the difficulty of dissolving 

 this medium in water. While the meat (250 grm.) for the infusion is 

 macerating in water, into a flask holding about 250 ccm. are poured 

 10 gim. of agar finely chopped up and 150 ccm. of Moselle wine. 

 Having been allowed to soak for a couple of hours, they are heated up 

 to boiling-point in a water-bath. When the pieces are dissolved the 

 agar-wine is set aside to cool. Next morning it is again liquefied in a 

 water-bath and neutralized with carbonate of soda. The gelatin-meat- 

 infusion, 2 per cent, gelatin, is then prepared in the usual way. When 

 ready the agar wine is added to it, the mixture boiled for a quarter of 

 an hour, and the whole filtered while hot. 



The fluid (20-30 ccm.) which flows through at first is somewhat 

 cloudy, but afterwards becomes quite clear. If cloudy the filtrate must 



* This subdivision contains (1) Collecting Objects, including Culture Pro- 

 cesses; (2) Preparing Objects; (3) Cutting, including Imbedding and Microtomes; 

 (4) Staining and Injecting ; (5) Mounting, including slides, preservative fluids, &c. ; 

 (6) Miscellaneous. t Berlin Klin. Wochenschr., 1887, p. 600. 



