446 CHAPTER XXXI II. 



on a slide with a drop of 40 per cent, solution of caustic potash, the slide 

 being warmed over a flame until the sections spread out flat. The excess of 

 potash is then removed and the sections are carefully washed with water, 

 covered, and examined. The safranin preparations may be permanently pre- 

 served in glycerin containing a small proportion of safranin. 



SCHAFFER'S safranin method (Zeit. f. icixtt. Mik., v, 1888, 

 p. 17, modified from BOUMA, Centralb.f. d. med. Wiss., 1883, 

 p. 866). Sections of bone decalcified with nitric acid (chromic 

 acid may be used, but the stain will be less brilliantly 'con- 

 trasted) are stained for half an hour to one hour in O05 per 

 cent, aqueous solution of safranin, washed with water, put 

 for two or three hours in O'l per cent, solution of corrosive 

 sublimate, and examined in glycerin. In order to make 

 permanent preparations, the sections on removal from the 

 sublimate are rinsed with alcohol, pressed on to a slide with 

 filter-paper, cleared for a long time in bergamot oil or clove 

 oil, and mounted in xylol balsam. 



This is a double stain ; cartilage, orange ; bone, uncoloured 

 (or green in chromic objects) ; marrow, red. 



BAYERL'S method for ossifying cartilage (Arch.f. 'mik. Anat , 

 1885, p. 35) is as follows : Portions of ossified cartilage 

 are decalcified as directed 578, cut in paraffin, stained in 

 Merkel's carmine and indigo -carmine mixture, o72, and 

 mounted in balsam. 



Aqueous solution of benzoaznrin has been commended as 

 a stain for ossifying cartilage by ZSCHOKKK, see Zeit. f. u'isf. 

 Mik., x, 3, 1893, p. 381. 



A process recommended by BAUMGARTEN has been given, 

 375. 



MOERNEE (Skandinavisches Arch. f. Pliysiol., \, 1889, p. 216 ; Zeit. f. 

 wiss. Mik., vi, 4, 1889, p. 508) gives several stains for tracheal cartilage, 

 chiefly as rnicrocheuiical tests, for which see third edition. 



See also a critique of these methods by WOLTEKS in Arch.f. mik. Anat., 

 xxxvii, 1891, p. 492; Zeit.f. iviss. Mik., viii, 3, 1891, p. 383 ; and on the 

 whole subject of cartilage see SCHIEFFERDECKER'S Gewebelehre, p. 331. 



FOSAKI (Arch. Ital. Biol., xxv, 1896, p. 200; Zeit. f. wiss. 

 Mik., xiii, 1896, p. 488) makes sections of fresh cartilage, 

 puts them for twenty-four hours into 1 per cent, nitrate of 

 silver, washes, dehydrates, and exposes to the light in 

 balsam. 



