The elements of pathological histology with special reference to practical methods / by Anton Weichselbaum ; tr. by W.R. Dawson.

  • Weichselbaum, A. (Anton), 1845-1920.
Date:
1895
Catalogue details

Licence: Public Domain Mark

Credit: The elements of pathological histology with special reference to practical methods / by Anton Weichselbaum ; tr. by W.R. Dawson. Source: Wellcome Collection.

Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.

    50/530 page 24
    Of Zeiss microscopes, the following combination would suffice for the same purpose :—Stand No. IV. (with nose-piece), objectives A and D, eye-pieces 3 and 4, magnifying 90-420 times; price, £12 10s. For bacteriological research. Abbe's apparatus and the homogeneous immersion xV (aperture, 1*20 ; magnification, 925) would have to be added, which raises the total, price to £21 5s. Generally speaking, microscopic examination should only be carried on by daylight. Should it be necessary, however, to resort to arti- ficial illumination, the yellow light of the flame should be corrected by means of a disc of blue glass laid on the eye-piece or mirror, or of an engraver's globe filled with ammonio-cupric sulphate (some drops of ammonia added to a solution of copper sulphate until it acquires a fine blue colour) and placed between lamp and microscope. [ADDITIONAL NOTE. The Gum Freezing Method.—The difficulty of freezing piece.s of tissue so that tlie sections shall not be spoiled by spicules of ice is very great. This may, however, be avoided by freezing in gum instead of water, and indeed for general use the latter method yields results little if at all inferior to those obtained by em- bedding in celloidin, whilst having the advantage of greater rapidity. When the tissue is hardened, the pieces, which should be thin, are freed from spirit by lying for twenty-four hours in water, and are then immersed in thick gum flntil thoroughly saturated, which requires from a few hours to some days, according to the density of the tissue, but the more protracted the soaking the better will be the results. It is then laid on the plate of the microtome, frozen, and cut into sections with a dry knife. It should not be frozen too hard, or the sections will be ridged, to obviate which syrup is sometimes added to the gum, as in the following mixture :—Syrup (28*5 grm. sugar to 30 c.cm. water), 4 parts ; mucilage (456 grm. gum acacia to 2400 c.cm water), 5 parts ; water, 9 parts. For delicate specimens a further addition of 1 part syrup to 2 of the mixture may be made. Fresh or imperfectly hardened tissues may also be cut by this method. The sections are transferred to tepid water in order to free them from gum, and may then be stained, etc., as usual, or kept in dilute spirit. For mounting, any of the media mentioned on p. 21 may be used, but Farranis solution is one of the best. It consists of a saturated solution of gum in equal parts glycerin and saturated arsenious acid solution. Preparations mounted in this must be subsequently cemented. Besides the much-used Cathcart microtome figured in the text, the freezing microtomes of Williams, Rutherford, or Bevan Lew^s may be used in making the sections. Freezing attachments can also be obtained for microtomes of the sliding type, such as Reichert's.]—Ti\
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