STAINS, ETC. 



of acid is removed from the tissue. Waldeyer's 

 Chlorpalladium Fluid. Palladium chlorid, one ctg., 

 and hydrochloric acid, ioooc.c. After decalcification, 

 wash the tissue thoroughly in water, and place succes- 

 sively in 30, 60, and 90 per cent, alcohol. 



DECOLORIZING, DIFFERENTIATING, AND 

 MORDANTING SOLUTIONS. 

 Acid Alcohol. Hydrochloric acid I c.c, absolute al- 

 cohol 70C.C, water 30 c.c. Acidulated Glycerin. 

 See Examination and Preservation Media. Acidu- 

 lated Water. Distilled water 1000 c.c, hydrochloric 

 acid 1 c.c. Anilin-water (Ehrlich). Shake up 3 

 c.c. of anilin-oil with 97 c.c. of distilled water, and 

 filter. The filtrate should be clear. Used as a mor- 

 dant for anilin dyes. It does not keep well, and 

 should be freshly prepared. Gram's Solution. 

 Iodin I part, potassium iodid 2 parts, distilled water 

 300 parts. This solution gives a reaction with tissues 

 which have undergone amyloid degeneration. It is 

 much used in the staining of microorganisms by 

 Gram's method. Lithia Water. Saturated aqueous 

 solution of lithium carbonate I c.c. , and distilled water 

 30 c.c, used as an intermediate agent in staining mi- 

 croorganisms. Lceffler's Mordant Solutions. 1. 

 Ten c.c. of a 20 per cent, solution of tannin, 5 c.c. of a 

 cold saturated solution of ferrous sulphate, 1 c.c. of an 

 aqueous or alcoholic solution of fuchsin (or I c.c of an 

 alcoholic solution of methyl-violet). 2. One percent, 

 solution of caustic soda. 3. Sulphuric-acid solution 

 of such strength that I c.c. will be completely neutral- 

 ized by I c.c. of I per cent, caustic-soda solution. 

 Nitric Acid. Pure nitric acid 10 c.c, distilled water 

 30 c.c. Used in the process of staining microorgan- 

 isms. Pal's Solution. Oxalic acid I gm. , potassium 

 sulphate 1 gm., distilled water 200 c.c. Used in staining 

 nerve-tissues after treatment with potassium permanga- 

 nate. Potassium Permanganate. In one per cent, 

 solution, used as a mordant for anilin dyes. In one- 

 quarter per cent, solution it is used to differentiate 

 tissues after staining with hematoxylin. Sul- 

 phanilic and Nitric Acid Solution. Saturated solu- 

 tion of sulphanilic acid 30 c.c, nitric acid (sp. gr. 

 1.42) 10 c.c. Used in the process of staining micro- 

 organisms. Sulphuric Acid Solutions, (a) Sul- 

 phuric acid (sp. gr. 1.84) 10 c.c, distilled water 30 

 c.c. (b) Sulphuric acid (sp. gr. 1.84) 10 c.c, alcohol 

 (90 per cent.) 90 c.c. Used in the process of staining 

 microorganisms. Toluidin Water. Toluidin 10 

 c.c, distilled water 90 c.c. Mix, agitate, and filter. 

 Used for the same purpose as anilin-water, and may 

 be substituted for it. Weigert's Differentiating 

 Fluid. Borax 2 gm., potassium ferricyanid 2.5 gm. , 

 distilled water 200 c.c Used after Weigert's 

 hematoxylin. 



DISSOCIATING FLUIDS. 

 These fluids soften and dissolve the interstitial material 

 of tissues, and facilitate the separation of their histo- 

 logic elements. I. Macerating Fluids. One-third 

 Alcohol. See Fixing Fluids. This is particularly 

 recommended by Ranvier for epithelia. Thin advises 

 one-fourth alcohol for dissociating the retina. Ammo- 

 nium and Potassium Sulphocyanid. A 10 per 

 cent, solution of either of these salts is recommended 

 by Stirling as a dissociating medium for epithelium. 

 Small pieces are macerated for 24 to 48 hours, and 

 may then be stained with eosin, fuchsin, or picrocar- 

 min. The fibers of a crystalline lens dissociated in ■ 

 either of these fluids become beaded or moniliform. 

 Ammonium Chromate. A 5 per cent, solution is used 



1372 DISSOCIATING FLUIDS 



for dissociating the " rodded " cells of the renal tu- 

 bules, cells of the salivary glands, Purkinje's fibers of 

 the heart, etc. It acts in 24 to 36 hours, and the 

 tissues must be well washed for preservation. Artifi- 

 cial Iodized Serum. See Examination and Preser- 

 vation Media. Artificial Saliva. Calberla's form- 

 ula : potassium chlorid 0.4 gm., sodium chlorid 0.3 

 gm. , sodium phosphate and calcium chlorid, each 0.2 

 gm., in 100 parts of water saturated with carbon di- 

 oxid ; of this solution one volume is combined with 

 one volume of water and half a volume of Miiller's 

 fluid. This mixture is recommended particularly for 

 dissociation of the developing muscle and nerve of 

 Ophidia and Amphibia. The tissue-elements are iso- 

 lated by teasing and shaking, and the preparation is 

 mounted in concentrated potassium-acetate solution. 

 Baryta Water. A 50 per cent, solution is useful for 

 dissociating white fibrous tissue, e. g. , tendon. Beale's 

 Fluid. The mucus expressed from the gastric glands 

 cf the pig is rapidly dried on glass plates, powdered, 

 and preserved in a stoppered bottle. Dissolve the 

 powder in distilled water or glycerin, and filter the 

 solution. Tissues are digested several hours in this 

 fluid at a temperature of 37 C. Eight-tenths of a 

 grain of the powder will dissolve 100 grains of coagu- 

 lated white of egg. The powder retains its proper- 

 ties for years. Brock's Medium. For the nervous 

 system of Mollusca : equal parts of 10 per cent, potas- 

 sium-bichromate solution and the visceral fluid of 

 the animal. Caustic Potash, Caustic Soda. Strong 

 solutions, 35 to 50 per cent., should be employed; 

 they do not greatly mar the forms of cells, while weak 

 solutions destroy them. The tissue may be treated 

 on the slide. Weak solutions may be employed for 

 dissociating the cells of hair, nails, and epidermis. 

 Professor and Mrs. Gage {Proceedings Am. Soc. 

 Microscopists, 1 889) have found that preparations 

 treated with these alkalies can be permanently pre- j 

 served by displacing the alkali with from 50 per 

 cent, to 60 per cent, of potassium acetate and then j 

 mounting in glycerin or glycerin-jelly. Chloral. A 

 mild, macerating medium in 2 to 5 per cent, solution. 

 It preserves delicate elements admirably, and is recora- \ 

 mended by Landowsky (Archiv. /. mik. Anat., \% 

 p. 359) for salivary glands ; by Hickson for the retina' 

 of Arthropods. Bela Haller's Mixture. One part 

 glacial acetic acid, I part glycerin, 2 parts water. 

 Recommended for the central nervous system of 

 Mollusca. Maceration is complete in 30 to 40 minutes 

 Hertwig's Liquid, for the nervous system of Medusa. 

 A mixture of equal parts of 0.05 per cent. osmi< 

 and o. 2 per cent, acetic acid. For Actina; 0.04 per < 

 osmic acid is used ; both the solutions are made in sea- 

 water, and the washing out is done in o. 2 per cent, ao 

 acid. Iodized Serum. See Examination and Pr 

 vation Media. It is used in the study of fresh tis 

 especially medullated nerve-fiber. A tiny fragment is 

 placed in 4 or 5 c.c. of weak serum in a closed v< si 

 and allowed to soak for a day or more, fresh iodin be 

 ing added as often as the serum becomes pale. W 

 sufficiently macerated, the tissue is teased or pr< - 

 out and mounted. Landois' Fluid. Dissolve 

 100 c.c. of distilled water 5 gm. each of neutral 

 monium chromate, potassium phosphate, and sodii 

 sulphate. This fluid is especially useful for tin 

 tral nervous system, and small pieces must lie 

 from one to five days. Mobius' Media. I. ' 

 part of sea-water and 4 to 6 parts of 0.5 per cenl 

 lution of potassium bichromate. 2. For Lamelli 

 branchiata : one per cent, each of osmic and ac 

 acids, and 0.25 percent, of chromic acid dis 

 sea- water. Miiller's Solution. See Fixin 



