Volume 1
A textbook of pathology : systematic & practical.
- Hamilton, David James.
- Date:
- 1889-94
Licence: Public Domain Mark
Credit: A textbook of pathology : systematic & practical. 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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![So far, the preparation is perfectly safe and can be kept indefinitely in this dried state, until such time as it may be convenient to expand and mount it, {cl) Stretching.—The gelatine, on account of the potash it contains, has now become so hygroscopic that if placed in water it will expand to nearly double its size, and, at the same time, the contained section Avill be stretched to a corresponding degree. As the water rushes in it also differentiates the gray from the white matter in a most remark- able manner. Water may be employed as the expanding agent, but Muller’s fluid is preferable. It is preferable because it cannot expand the preparation too much nor irregularly; it defines the gray and white matters better ; and lastly, but not of least importance, it removes any insoluble deposit which may have been thrown down in the gelatine. The sections ought to be left in a flat porcelain trough for a night thoroughly covered by the Muller’s fluid, the labels being allowed to hang over the side. They are afterwards placed in a running stream of water, until all trace of the Muller’s fluid has vanished. The supply of water should be free, and where a number of preparations are lying together, their position should be altered from time to time, so as to get rid of the colour as soon as possible. It usually requires about two hours; and as soon as this has been done they are laid in a mass on a sloping surface so as to drain off as much of the water as possible. {e) Mounting.—They are next immersed again in the mixture of Liquor Potassse and water (1 to 2) and alloAved to remain for about an hour and a half. The greatest care, however, should be exercised, that they do not remain beyond this, as the gelatine will become softened and the preparation so ruined. What is required is to get the exquisite transparency which this procedure occasions. As soon as this is obtained they are to be withdrawn on a clean sheet of glass. The tie-label is now cut off, and, as the preparation is to be perman- ently mounted on this slide, a fresh one is gummed on to one of its corners. The slide is placed in a sloping position; and as soon as all the extra liquid has been removed, the preparation is covered with the following glycerine jelly dropped on at a low temperature (80° to 90° F.) with a pipette: — Soak French gelatine in water for ten minutes. ]\Ielt in a water bath and to 20 oz. of this add 20 oz. of water. To 40 oz. glycerine add If oz. liquid carbolic acid, and stir this gradually into the gelatine solution. Filter through sieve cloth. When the glycerine jelly has thoroughly set, grease the label with lard as before, and place in an alkaline bath having this composition,— Glycerine ...... 1 part. Liq. Potassse (Phar. Brit.) ... 2 parts. Add Carbolic Acid in proportion of . I to 40 parts. Allow them to remain for at least twelve hours in this. They take no](https://iiif.wellcomecollection.org/image/b24990607_0001_0078.jp2/full/800%2C/0/default.jpg)
