4 PRACTICAL HISTOLOGY. 



5. Most of the requisite tissues and organs may be ob- 

 tained from the cat and guinea-pig. Feed the cat, and an 

 hour or so afterwards place it in a bag ; drop chloroform 

 over its nose until insensibility is produced. Open the 

 chest by a linear incision through the sternum ; speedily 

 open the right ventricle, and allow the animal to bleed to 

 death. 



6. Divide the trachea immediately below the cricoid 

 cartilage, and inject it with ^ per cent chromic acid fluid ; 

 tie it to prevent the escape of the fluid, and place the dis- 

 tended lungs in the same fluid, and cover them with cotton 

 wool. Change the fluid at the end of eighteen hours. 

 Allow them to remain in this fluid for a month, then cut 

 into small pieces and transfer to rectified spirit* until 

 required. 



7. Open by a linear incision the stomach, small and 

 large intestine, and wash their inner surface with -J per cent 

 salt solution. Place the tongue, divided transversely into 

 a number of pieces, and a portion of the small intestine in 

 chromic and bichromate fluid (Solution 4). Change the 

 fluid at the end of eighteen hours ; and at the end of a 

 fortnight transfer them to rectified spirit until required. 

 Place the tongue, divided transversely into five or six 

 pieces, together with a portion of the stomach and large 

 intestine, in per cent chromic acid solution. Change the 

 fluid at the end of eighteen hours fand at the end of a 

 month transfer them to rectified spirit till required. 



8. Open the bladder, wash it with salt solution, and 

 place it in a i per cent solution of bichromate of potash 

 (Solution 7) for two or three days. 



9. Remove the kidneys ; divide one transversely, 

 the other longitudinally, and place them in Mullens fluid. 

 Change the fluid at the end of eighteen hours ; and at the 

 end of four weeks transfer them to rectified spirit until 

 required. They will be ready after having been a fortnight 

 in the spirit. It is also advantageous to have the kidneys 



* In this edition rectified spirit has been substituted for methylated 

 spirit in the preparation of the tissues, for undoubtedly the tissue ele- 

 ments are better prepared in it. (Its sp. gr. is 0-838.) 



