Methods of morbid histology and clinical pathology / by I. Walker Hall and G. Herxheimer.

  • Hall, I. Walker (Isaac Walker), 1868-
Date:
1905
Catalogue details

Licence: In copyright

Credit: Methods of morbid histology and clinical pathology / by I. Walker Hall and G. Herxheimer. Source: Wellcome Collection.

    32/316 (page 12)
    Place a drop of the reagent at one side of the cover- glass and a small piece of filter-paper at the other; by this method the reagent enters the capillary space between the slide and the cover-glass and passes towards the blotting- paper. The changes induced in the tissue during its progress can be observed under the low or high power. Amongst many others, the following chemicals deserve special mention :— 1. Acetic Acid.—This acid causes the nuclei to shrink slightly and to stand out more boldly. It is also useful in the demonstration of elastic fibres, which, being unaffected by acetic acid, are sharply defined from the connective tissue, which swells under its influence. Acetic acid differentiates albuminous and fatty granules, dissolving the former and not affecting the latter. A 1-5 per cent solution is generally employed, but in some cases the concentrated acid may be used. In the latter instance the acid is of course diluted in proportion to the amount of fluid already underneath the cover-glass. The addition of a few drops of a dye—as, for instance, fuchsin—to the acetic acid makes the nuclei still more distinct. 2. Caustic Potash (1-3 per cent).—Elastic fibres, pigments, fat, and bacteria are not acted upon, and so are more easily recognised ; the greater part of the other tissue structures become unrecognisable. 3. Osmic Acid (1 per cent) and the recently introduced Sudan III. and Scharlach R stain fat globules black and red respectively, thus rendering them distinctly visible. 4. Mineral Acids—HC1 or H2S04 (3-5 per cent).—The former liberates CO., from calcium carbonate, and effervescence occurs ; the latter produces calcium sulphate crystals. 5. Iodine Solution (Lugol’s solution diluted with water).—This, in a manner similar to acetic acid, brings out the nuclei and cell contours, and is especially useful in that it yields a specific reaction with amyloid or lardacein. While it stains the tissues yellow, the amyloid material is coloured mahogany brown (see Amyloid). When the glycogen has not been washed out or dissolved by the solutions employed, it also is stained brown. 6. Stains (fuchsin, methylene blue, methyl green).—1 per cent solutions of these dyes in water, or preferably normal saline solution, are of great value in the examination of fresh tissues. They are drawn under the cover-slip by means of blotting-paper.