THE MICROSCOPE IN ANIMAL HISTOLOGY. 225 



Cut one-half of the liver into small pieces and prepare 

 as the kidneys. The tongue, divided transversely into five 

 or six pieces, the spleen, uterus, and thin muscles from 

 limbs or abdomen, in J per cent, chromic acid. Change as 

 before, and in a month to methylated spirit. 



Testis of dog, freely incised, and ovaries of cat or dog, in 

 Muller's fluid, and after three weeks to methylated spirits. 



Divide the eyes transversely behind the lens. Remove 

 the vitreous. Place posterior halves in chromic and spirit 

 solution. Change in eighteen hours. Transfer to methy- 

 lated spirit in ten days. Place the lens in Muller's fluid 

 for five weeks, and then in methylated spirits. The cor- 

 nea may remain in J per cent, chromic acid for a month, 

 and then in methylated spirit. 



Cautiously open the cranial and spinal cavities. Re- 

 move brain and cord, and strip off arachnoid. Partially 

 divide the cord into pieces a half inch long. Partially 

 divide the brain transversely into a number of pieces. 

 Place in a cool place in methylated spirits for eighteen 

 hours. Transfer cord to J per cent, chromic acid for six 

 or seven weeks. Change in eighteen hours. Prepare the 

 sciatic nerve in the same manner. Place the brain in 

 chromic and bichromate fluid. Change in eighteen hours, 

 and then once a week, until the brain is hard. If not 

 leathery in six weeks place in J per cent, chromic acid for 

 two weeks, and then in methylated spirits. Support the 

 brain and cord on cotton-wool in the hardening fluid. 



Remove muscles, but riot periosteum from bones of 

 limbs, and both from the lower jaw. Divide the bones 

 transversely in two or three places, and put them in chro- 

 mic and nitric fluid (chromic acid, 1 gramme ; water, 200 

 c.c. ; then add 2 c.c. nitric acid). Change the fluid often 

 until the bone is soft enough, and transfer to methylated 

 spirits. If not complete in a month, double the quantity 

 of nitric acid in the fluid. 



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