The human brain : histological and coarse methods of research : a manual for students and asylum medical officers / by W. Bevan Lewis.

  • Lewis, William Bevan, 1847-1929.
Date:
1882
Catalogue details

Licence: Public Domain Mark

Credit: The human brain : histological and coarse methods of research : a manual for students and asylum medical officers / by W. Bevan Lewis. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    first occurs when glycerine or otlier medium Avliicli cannot be frozen has been accidentally smeared over the plate—the latter usually from want of rapid manipulation on the part of the operator, or too warm an atmosphere for satisfactory freezing. 8. Lastly, the uell or freezing chamber may he. too s))i'iU, in which case freezing is not only retarded, but subsequent thawing is hastened. For my own part I would strongly recommend this portion of the instrument to be full 2 inches in diameter by inches deep. We now proceed to the subsequent treatment of oiu' sections. Staining Fresh Sections of Cortex.—In this stage our sections pass through two processes—the osmic acid treat- ment and aniline staining. Take a perfectly clean glass slide, pass it beneath a section floating in water, and, fixing it to the slide by a needle, remove it carefully, draining off all superfluous fluid from the slide. E/cmove each section in a similar way, and next, by means of a pipette, let two ortlii^ee drops of osmic acid solution (0*25 per cent.) fall on the slide and float up the section ; with a pen-knife carefully spread this fluid over the upper surface of the section, which, on account of the repulsion afforded, gives a little trouble witli extremely thin films. This procedure is, of course, not necessary where the section has been sunk in water, but the more delicate sections float, and can be plunged beneath the surface of the water only at the risk of ruining them. A little practice soon enables us to carry the osmic acid over the most delicate films without tearing them. Sections thus treated should not remain over one minute in the osmic acid of the strength named, but should at once be immersed in a vessel of pure water and left here for five or ten minutes. By this time all superfluous acid has been removed, and the osmium has fixed the nervous structures, so that they are manipulated without danger and do not deteriorate in water. The sections may now be stained collectively, or, as I prefer