I.] DISSECTION OP A BABBIT AND OF A DOG, 33 



the muscular surface downwards, stretching it 

 slightly, and place it in alcohol about 75 p. c. for 

 about an hour, then remove to 95 p.c. alcohol for 

 a fortnight ; keep in 75 p.c. alcohol. 



2, Cut out of the small intestine a piece about two 

 inches long ; tie into each end a short glass tube 

 with lumen about 5 m.m. in diameter, over the 

 free end of each glass tube slip a piece of india- 

 rubber tubing ; by means of a syringe wash out 

 the piece of intestine with NaCl'6 p.c. for 

 about twenty seconds, then inject chromic acid 

 •2 p. c. When the salt solution has been displaced 

 by chromic acid tie or clamp the peripheral piece 

 of tubing, inject a little more chromic acid to 

 distend slightly the intestine, and tie or clamp 

 the central piece of tubing. Place the distended 

 intestine in ten times its bulk of chromic acid 

 •2 p. c. In two to three days cut off both ends 

 of the intestine, cut it open longitudinally, and 

 place it in fresh chromic acid '2 p. c. ; in about 

 ten days place it in water for some hours, and 

 then in alcohol 30 p.c. ; on the next day transfer 

 it to alcohol 50 p.c. renewing the alcohol as long 

 as it becomes coloured and finally place the tissue 

 in strong spirit. 



3. Take a piece of costal cartilage about 5 m.m. 

 long and place it in about 10 c. c. of saturated 

 aqueous solution of picric acid ; after about ten 

 days wash it well with water and place for a 

 day in 50 p.c. alcohol, then transfer to strong 

 spirit. 



L. 3 



