64 FIXING AND HARDENING AGENTS. 



MARCHOUX (from PEREZ, Arch. Zool. Exper., v, 1910, p. 11) takes 

 11 parts 1 per cent, chromic acid, 1 of acetic acid, 4 of water, and 16 of 

 formol (added just before using). 



These mixtures are neither so good nor reliable as Bouin's picro- 

 formol. 



115. Copper Formol. NELIS (Bull. Acad. Sc. Belg., 1899 (1900), 

 p. 726) fixes spinal ganglia for twenty-four hours in 1 litre of 7 per cent, 

 formol with 5 c.c. of acetic acid, 20 grms. of cupric sulphate, and sub- 

 limate to saturation. 



STAFFERS (La Cellule, xxv, 1909, p. 356) used (for Sympoda) a mixture 

 of G-ILSON'S : 100 parts of formol of 5 per cent, with 2 of nitrate of 

 copper. 



STRONG (Journ. Comp. Neur., xiii, 1903, p. 296) fixes the head of 

 Acanthias by injecting a mixture of equal parts of formol and 5 per 

 cent, solution of bichromate of copper. 



116. Nitric Acid Formol. WILHELMI (Fauna u. Flora Golf. Neapel, 

 xxxii, 1909, p. 15) fixes Triclads in APATHY'S mixture of equal parts of 

 6 per cent, nitric acid and 6 per cent, formol, and brings them direct 

 into strong alcohol. 



117. Acetone Formol. BING and ELLERMANN (Arch. Anat. Phys., 

 Phys. Abth., 1901, p. 260) fix medullated nerves in 9 parts of acetone 

 with 1 of formol. , 



