114 PRACTICAL HISTOLOGY. 



purpose), and one end being tied up, a glass canula 

 is fastened into the other end, and the piece of 

 intestines having been distended with air, this also 

 is closed by a ligature and the canula removed. The 

 outer surface is then brushed vigorously with a 

 camel-hair pencil wetted with distilled water to 

 remove the epithelioid cells of the serous membrane ; 

 a few drops of a solution of nitrate of silver (i per 

 cent.) are allowed to flow over the brushed surface 

 and to remain in contact with it for two minutes, 

 the silver solution is then washed off by a stream of 

 distilled water, and finally the distended intestine 

 is immersed in a mixture of equal parts of water 

 and spirit in a beaker and exposed to the light. The 

 immersion is effected either by tying a piece of 

 glass rod or other heavy substance to the gut, or by 

 filling the beaker to the brim and placing a glass 

 plate over it so as to press the piece of intestine 

 under the surface of the fluid. In about an hour's 

 time the preparation may be removed from the 

 light (a few minutes will be sufficient if it is bright 

 sunlight), and a small piece is then to be cut out 

 and mounted in glycerine with the outer surface 

 uppermost. 



Preparation 3. Voluntary muscular tissue : 

 cross-striped muscle. For the examination of 

 this tissue in mammals the animal from which the 

 preparation is to be taken should have been killed 

 some hours previously, in order to obviate the 

 shrinking and contraction which would otherwise 

 take place in a freshly-severed portion of muscle 

 placed in fluid, and would obscure many of the 

 structural appearances. A small longitudinal shred 

 is torn or stripped oft' from any muscle of the limbs 

 or trunk, placed in a drop of serum upon a slide, 

 and the fibres are slowly and carefully separated 

 from one another, one by one, for as great a length 

 as possible. A very small slip of blotting-paper is 

 then placed by the side of the preparation to avert 

 the pressure of the cover-glass (a hair is not, in this 



