NERVOUS SYSTEM— GENERAL METHODS 467 



in 10 per cent, formol, put for ten to fifteen minutes into acetone, 

 then for twelve hours into cliloroform, and imbeds in paraffin. 

 He has also a process with trichloracetate of lead and 

 methylenazur. 



Strecker {Zeitschr. iviss. Mikr., xxviii, 1911, p. 17) recom- 

 mends equal parts of 10 to 20 per cent, formalin and of Erhlich- 

 Biondi tri-acid stain for twenty-four to forty-eight hours. And 

 also 3 parts of toluidin blue in 100 parts of 10 per cent, formalin, 

 fixing the blue thereafter with Bethe's ammonium molybdate 

 solution. 



Ilberg {New. Centralb., xv, 1896, p. 831) fixes in 96 per cent, 

 alcohol, and stains pieces in Nissl's soap solution of methylen 

 blue for five to ten days, differentiating in 96 per cent, alcohol 

 for two to three days, changing it every day. Imbed in paraffin 

 and further differentiate the sections, if necessary, in 96 per cent, 

 alcohol. 



999. Da Fano {Journ. Physiol., Ix, 1925, p. 1) fixes small 

 pieces of fresh tissue in Bouin's fluid, transfers to 70 to 80 per 

 cent, alcohol overnight and then places in fresh alcohol of the 

 same strength to which is added 1 per cent, lithium iodide, renew- 

 ing this every day till the picric acid is almost entirely removed. 

 Wash overnight in running water and then for some hours in 

 distilled water, and transfer to Scott's modification of Ehrlich's 

 haematoxylin diluted with 3 parts either of distilled water or 

 of 2 per cent, acetic acid. (Scott's formula (J, Path. & Bad., 

 xvi, 1911-12, p. 890), glycerol 100 c.c, water 100 c.c, 

 alcohol (96 per cent.) 100 c.c, glacial acetic acid 10 c.c, potash 

 alum 7 grm., haematoxylin 1 to 1-25 grm. ; ripen several months.) 

 Leave in this for two to three weeks according to thickness of 

 pieces, changing the hannatoxylin at the end of the first week. 

 Wash quickly and put for two to three hours into acid alcohol 

 (1 per cent. HCl in 70 per cent, alcohol). Wash overnight in tap- 

 water. Pass through the alcohols up to 95 per cent, and thence 

 place in 1 per cent, eosin in 95 per cent, alcohol for one week. 

 Wash in 95 per cent, alcohol for two to twenty-four hours. Dehy- 

 drate, clear and imbed in paraffin. 



CuMMiNGS {J. Comp. Neur., xxxviii, 1925, p. 401) fixes and 

 stains the membranous labyrinth of the rat as follows : Fix for 

 twenty-four to forty-eight hours in a modified Held's fluid. 

 (Formalin 4 parts, glacial acetic acid 5 parts, 3 J per cent. pot. 

 bichromate 91 parts.) Wash for twenty-four hours in running 

 water, dehydrate up to 80 per cent, alcohol and decalcify in 

 3 per cent. HNO3 in 80 per cent, alcohol. Pass through gradually 

 weaker alcohols to 25 per cent, alcohol and then stain in diluted 

 Delafield's ha?matoxylin or Mann's methyl blue eosin for three 

 to five days. Dehydrate, adding a drop of ammonia to the 

 alcohol, infiltrate with celloidin and cut by dry cedar oil method. 



