THE (ESOPHAGUS AND STOMACH. 211 



CIIAPTEE XIY. 



THE (ESOPHAGUS AND STOMACH. 



Preparation 1. The oesophagus is best hardened 

 for the preparation of sections by a mixture of equal 

 parts of chromic acid (J per cent, solution) and spirit. 

 After three or four days in this the tissue may as usual 

 be transferred to spirit. Before putting it into the 

 mixture it should, if but a small piece be employed, 

 be pinned out upon a piece of cork, so as to stretch 

 it slightly and avoid folds. But if a tubular piece 

 be available this object may be effected more satis- 

 factorily loy distending the organ with the preserva- 

 tive solution through a glass canula tied into one 

 end, the 6ther end having been secured by a ligature 

 before the distension ; the piece is then immersed in 

 the mixture for twenty-four hours, after which it 

 may be cut open. In embedding the gullet and 

 other membranous parts, of which it is desired to 

 obtain sections vertical to the surface, it is well to 

 proceed in a way somewhat different from usual, the 

 transfixion with a pin being discarded. A layer of 

 the melted wax-mass is first poured into the mould 

 so as to fill it nearly half-full ; the piece of gullet to 

 be embedded is deprived of all superfluous moisture 

 by placing it on blotting-paper for a few seconds, 

 and then, as soon as the wax-mass in the mould is 

 hard enough to support its weight, it is placed in the 

 desired position near one end of the box, which is 

 filled up with more wax-mass. This, especially if a 

 few degrees above its melting-point, adheres firmly 

 to the portion of the wax-mass which was first 

 poured in, so that the whole forms a uniform cake, 

 with the tissue embedded in it. 



