The essentials of histology, descriptive and practical, for the use of students.

  • Sharpey-Schäfer, E. A. (Edward Albert), Sir, 1850-1935.
Date:
1902
Catalogue details

Licence: In copyright

Credit: The essentials of histology, descriptive and practical, for the use of students. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

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    slick', the water diaiiied oH', the ti.s.siie allowed to dry coiiipletely, and daiiiiuar added. This iiiethud is used to e.xliibit eiidotlieliuui, and generally to .stain intercellular substance. It depends upon the fact that the ehhjrides of the ti.s.sues are almost e.xclusively confined to the intercellular substance. The following methods are especially useful in investigations relating to the nervous system : 21. Marcki's solution.—This is a mixture of Miiller's Huid (2 parts) with 1 per cent, osmic acid (1 part). It is of value for staining nerve-fibres in the earlier stages of degeneiation, before sclerosis .sets in (especially a few days after the establishment of a lesion). All the degenerated meduUated fibres are stained black, whilst the lest of the section remains almost unstained. It is best to put thin pieces of the brain or cord to be inve.sti- gated singly into a large quantity of the solution (after previously hardening for ten days in Midler's fluid), and to leave them in it for a week or more ; if necessary sections can be stained; in this case the process is more complicated.' In either case they are fixed on a slide and mounted by the usual i^iocess in xylol balsam or dammar. 22. Weiqert-Pal method.—This method is chiefly used for the cential nervous system. By it all meduUated nei-ve-tibres are stained dark, while the grey matter and any sclerosed tracts of white matter are left uncoloured. The following modification of the original method can be recommended : Pieces which have been hardened in Miiller's fluid and afterwards kept a short time in alcohol (without washing in water) are embedded in cel- loidin, and sections are cut as thin as possible. Or sections may be made by the freezing method direct from Miiller's fluid, if the tissue is first soaked in gum-water foi' a few hours. In either case they are placed in water, and from this are transferred to Marchi's fluid (.see above, g 21), in which they are left for a few hours. They are then again washed in water and transferred to Kulschitzky's hffimatoxylin (see above, § 3). In this they are left overnight, by which time they will be completely black. After again washing in water they are ready to be bleached. This is accompli.shed by Pal's method as follows: Place the overstained sections, flrst in 5 per cent, solution of potassium permanganate for Ave minutes (or for a longer time in a weaker solution) ; rinse with water and transfer to Pal's solution (sulphite of soda 1 gramme, oxalic acid 1 gramme, distilled water 200 cubic centimetres), in which the actual bleaching takes phice.- They are usually sufiiciently ditterentiated in a few minutes : if not, they can be left longer in the solution without detriment. If aftei- half an hour they are not ditterentiated enough, they must be put again (after wa.shing) into the permanganate for some minute.s, and then again into Pal s .sohition. After diflerentiation they arc passed through water, alcohol (with oi- without eosin), and oil of bergamot (or xylol), to be mounted in xylol baksam or dammar. The advantages which this modilication has over the original method are (1) even the flnest meduUated iibres are brought to view with ' See Hamilton, lirain, 18!)7, p. 180. - Diluted sulphurous acid solution may be employed instead of Pal's solution.