ZOOLOGY AND BOTANY, MIGBOSCOPY, ETC. o'J9 



paration dehydrated in absolute alcohol, cleared in xylol, and mounted 

 in balsam. 



(2) Wet method. The still wet film is fixed in corrosive sublimate 

 (Muir) or in 2 per cent, formol, and then, having been washed, is treated 

 with the fixative described in the dry method, which is allowed to act 

 for 2 minutes. The preparation is then successively washed in water, 

 alcohol, and water, after which it is stained with eosin and again washed. 

 Some saturated solution of potash-alum is now dropped on and allowed 

 to act for 2 minutes, after which the preparation is washed in water, 

 and then stained with methylen-blue. The film is again washed, then 

 dehydrated, cleared up, and mounted as before. In this method the film 

 must not be allowed to dry at any stage. Carbol-thionin-blue may be 

 used instead of methylen-blue ; the film is then fixed in sublimate. These 

 methods give good results with sections. 



Safranin Staining.* — Dr. L. W. Ssobolew has found that sections, 

 especially celloidin sections which have lain long in alcohol and do not 

 stain well with safranin, may be successfully stained by remordanting 

 them with Flemming's fluid. The sections should be immersed in a 

 mixture of 10-15 drops of this fluid and 5 ccm. of distilled water for 

 5-10 minutes. They are then washed, and stained with saturated aqueous 

 solution of safranin. The after treatment is the same as usual. 



Method for Fixing and Staining Nervous Tissue, f — Mr. A. P. 

 Ohlmacher has used the following modification of Carnoy's fluid for a long 

 time on account of its great penetrating and hardening properties : — 

 absolute alcohol, 85 parts ; chloroform, 15 parts ; acetic acid 5 parts ; 

 sublimate to saturation (about 20 grm.). Small pieces of tissue are 

 hardened in a quarter to half an hour ; large slices require 18 to 24 

 hours. After hardening, the pieces are washed, and may be kept in 

 80 per cent, alcohol. The fluid may be used several times. The stain- 

 ing procedure recommended by the author is to stain for a minute in 

 Ehrlich's anilin-gentian violet, then drain off the superfluous fluid, and 

 wash in water. Treat with picrio acid-fuchsin solution (0 ' 5 per cent, 

 acid fuchsin to a saturated solution of picric acid which is diluted with 

 an equal volume of water). Dehydrate with absolute alcohol. Clear up 

 in clove oil, and mount in xylol-balsam. 



Modification of Kronthal's Method of Staining Nervous Tissue.:}: 

 — Herr H. K. Corning states that he has obtained better results by fixing 

 and hardening in 10 per cent, formalin previously to immersing in the 

 lead formate mixture. Moreover, instead of the lead formate obtained 

 by dropping formic acid into saturated solution of acetate of lead, he 

 uses Merck's plumbum formicum. Though Kronthal's method § possesses 

 some advantages over that of Golgi, the penetrating power of the fluids 

 (the original and the modified) is not great, and does not reach deeper 

 into the piece of tissue than 3-4 mm. 



Method of Staining Medullated Nerve -fibres en bloc, and a 

 Modification of Marchi's Method.[| — Dr. D. Orr states that he has 



* Zeitschr. f. wiss. Mikr., xvi. (1900) pp. 425-6. 



t Bull. Ohio Hosp. Epilept., 1898. See Zeitschr. f. wiss. Mikr., xvi. (1900) 

 pp. 435-6. % Anat. Anzeig., xvii. (1900) pp. 108-11. 



§ Cf. this Journal, 1899, p. 548. 

 || Journ. Pathol, and Bacterid., vi. (1900) pp. 387-93 (1 pi.). 



