502 APPENDIX. 



893, Iron Hsematoxylin (Addendum to 255, p. 191) .HELD 

 (op. cU. t SuppL, p. 158) finds it an improvement to add to 

 the staining bath a very little of the iron-alum solution until 

 a scarcely perceptible precipitate is produced. 



894. Neuro-fibrils (Addendum to 707). BETHE (Zeit. 

 f. wiss. Mik., xvii, 1, 1900, pp. 13 35) has now minutely 

 described the method mentioned on p. 395. Pieces of central 

 nervous system are fixed for twenty-four hours in nitric acid 

 of from 3 per cent, to 7*5 per cent, strength, and brought 

 direct into alcohol of 96 per cent, for a day or more. They 

 are put for twelve to twenty -four hours into a mixture of one 

 part of ammonia (of sp. gr. 0*95) with three of water and 

 eight of 96 per cent, alcohol, then for six to twelve hour's 

 into a mixture of one part concentrated nitric acid with three 

 of water and eight to twelve of alcohol, then for ten to 

 twelve into pure alcohol, and thence for not more than two 

 to six hours into water. They are now mordanted for twenty- 

 four hours in a 4 per cent, solution of ammonium molybdate, 

 brought for twenty-four hours into alcohol, and imbedded 

 in paraffin (not celloidin). Sections are seriated on albumen 

 and " differentiated " by which the author means washed 

 out with water. About 1 to 1*5 c.c. of distilled water 

 should be poured on to the slide so as to form over the 

 sections a layer 1*5 to 2 mm. deep, and the slide is put for 

 two to ten minutes into a stove heated to not more than 

 55 to 60 C. The sections are then rinsed several times, 

 with water, a solution of one part of toluidin blue in 3000 

 of water is poured on to them, they are again stoved for 

 ten minutes, rinsed with water, treated with 96 per cent, 

 alcohol till no more colour comes away (three quarters to 

 two minutes) , and passed through absolute alcohol and xylol 

 into xylol balsam. 



For the very elaborate minutiae described by the author 

 the reader must consult the original. 



