The elements of embryology. / By M. Foster ... and Francis M. Balfour.

  • Michael Foster
Date:
1874
Catalogue details

Licence: Public Domain Mark

Credit: The elements of embryology. / By M. Foster ... and Francis M. Balfour. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    275/336 (page 249)
    it must be hardened with alcohol. We cannot howevei' recommend this substance for embryos. For the method of employing it, see JELand-booh for the Physiological Laboratory, p. 92.] The exact consistency of these various mixtures should be made to vary according to the solidity of the embryo, by increasing or diminishing the various constituents. From a cold solid mass of one of the mix- tures, cut a cubical block (about an inch cube), and on one surface make a shallow cavity, large enough to receive the blastoderm. Having with a morsel of blotting-paper removed all superfluous alcohol from the blastoderm place it quite flat in the cavity just made, and gently pour over it some of the mixture sufficiently heated to have become liquid (care being taken, of course, that it is not too hot). With a heated needle, remove any bubbles that may make their appearance ; and make on the block, as a guide in. cutting the sections, a mark of the exact position of the embryo. It is sometimes of advantage to transfer the embryo from the alcohol to some oil of cloves (when the wax and •oil is used, or to some creosote, when the paraffin is employed), and to allow it to become saturated with that substance, before placing it in the block. The adhesion of the imbedding material to the object imbedded, is thus rendered more complete. This method serves fairly well, when there are no cavities in the object into which it is necessary for the mixture to penetrate. When these exist, the following method (again Dr Kleinenberg's) will be found the most satisfactory, Kemove the object from the absolute alcohol and place it directl}^ into Bergamot oil, and leave it there, till the oil has completely penetrated through it. In the mean time, prepare a small paper box, by bending up the sides and folding in the corners of a piece of stifif paper, and pour on the bottom of it a thin coating of the mixture of spermaceti and castor oil. When this has become solid, place the