A text-book of histology / by Frederick R. Bailey.

  • Frederick R. Bailey
Date:
1913
Catalogue details

Licence: Public Domain Mark

Credit: A text-book of histology / by Frederick R. Bailey. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    29/674 page 5
    caustic alkali, this may be accomplished by neutralizing with glacial acetic acid or by replacing the alkali with a 6o-per-cent. aqueous solution of potassium acetate. The specimens may then be preserved in the potassium-acetate solution, in glycerin, or in 50-per-cent. alcohol. This dissociating fluid is largely used for muscle cells and fibres. {d) Nitric acid (10- to 20-per-cent. aqueous solution).—This is especially useful for dissociating involuntary and voluntary muscle. After any of the above procedures, the macerating fluid containing the tissue elements should be placed in a long tube, allowed to stand for a time and the fluid decanted. Water is then poured into the tube, the tissues allowed to settle and the water poured off, this being repeated until all trace of macerating fluid is removed. The tissue elements may then be preserved or mounted in glycerin or in glycerin jelly. It is frequently advisable to stain the tissues. For this purpose alum-carmin (p. 19) is especially satisfactory. (For details see technic i, p. 124 and technic 2, p. 124), After staining and wash- ing, the tissues may be preserved or mounted in glycerin, eosin glyc- erin, or glycerin jelly. It frequently happens that on examining dissociated tissue elements after mounting, the bits of tissue are still too large. This may be remedied by gently tapping on the cover-glass with a lead pencil. PREPARATION OF SECTIONS I. Fixation Even tissues, the structure of which admits of their being exam- ined in the fresh condition, as described on p. 3, soon undergo post-mortem changes if placed in an inert medium such as normal salt solution or blood serum. As a result they soon lose their char- acteristic appearance and disintegrate. A proper killing or fixation is therefore the first step in the preparation of most tissues for micro- scopic study, the object being to so preserve the tissues that they retain as nearly as possiljlc, and more or less permanently, the same structure and relation which they had during life. Fixed tissue may be placed in water, salt soluticm, alcohol, etc., in fact may be subjected to many and varied manipulations which would destroy fresh tissues, without disturbing the relation of the tissue elements. Fixation of such a thin film of tissue as a blood smear may be accomplished by
    digitised image 1
    digitised image 2
    digitised image 3