| Popis: |
A number of non-volatile, water-soluble substances can be added to the usual aceto-cannine fixing fluids. These inert substances do not alter the fixation image and serve as mounting media when the volatile ingredients of the mixture evaporate. Formulae are given for solutions containing dextrin, dextrose, gelatin, pectin, sorbitol, and sucrose. Gum arabic can be incorporated in a formic-acid-carmine fixative. The limiting factor in the use of such mounting media in fixing fluids is the osmotic value they give the solution; with certain precautions, however, they can be used in place of the usual aceto-carmine treatment. The indices of refraction of these media are not as high as those of the natural balsams and the fixation images which the mixtures produce have the characteristic limitations of those secured by the aceto-carmine technic. Some of the natural balsams (Canada balsam, sandarac and Venetion turpentine) can also be incorporated in fixing fluids. These fixatives are able to hold balsam and wat... |
