The Micrographic Dictionary; A Guide to the Examination and Investigation of the Structure and Nature of Microscopic Objects (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1856 Excerpt: ... the microscope, when, if central and fixed, the enclosed body will retain this position; and if it be less than the cavity of the enclosing structure, positive indication will be afforded that the latter is solid, or at least that it does not consist simply of an outer coat with liquid contents and the enclosed body. But if it be attached to the inner wall of the enclosing structure, the eccentricity of its motion whilst revolving will be evident. The contents of microscopic bodies are frequently rendered distinct by the addition of reagents, and in some cases can alone be distinguished by their use; thus the nuclei of animal cells are at once made evident by the addition of acetic acid, &c. We frequently have to decide whether the interior of an object is solid or tubular. If it consist of a firm substance, drying it, if in liquid, will cause the evaporation of the liquid or other contents, and the entrance of air. A section of it will also show whether it is solid or hollow. The effects of crushing it should also be observed. B. Histological Analysis. This consists in the resolution of the object into its component morphological elements, and is usually effected by subjecting it to the action of various chemical reagents, continued maceration, &c. It must never be attempted if inorganic matters be present in quantity, until these have been previously removed. The reagent used should be one which exerts a solvent action upon the substance of which the object is composed, the action being interrupted at a certain stage by the addition of water, &c. In regard to those CHEMICAL REACTIONS. xxxvii objects whose morphological elements have become altered by individual growth, &c., histological analysis is of course useless; and the manner in whi...