424 SOME OTHER HISTOLOG10AL METHODS. 



by ether) ; lay them again flat on glass, and cover them with 

 a double layer of blotting-paper and a somewhat heavy glass 

 plate, and let them dry for a day in the air or in a stove. 

 When they are dry, put a drop of melted balsam on a slide, 

 and let it spread out flat and cool. Prepare a thin glass 

 cover in the same way, put the section on the prepared 

 slide, cover it with the prepared cover, put on a clip, and 

 warm. 



By this process sections can be very expeditiously pre- 

 pared, which show the lacunar system injected with air in 

 quite as instructive a manner as non-decalcified sections. 



KOLLIKER (Zeit. f. wiss. Zool.j xliv, 1886, p. 662) recom- 

 mends the following process for the demonstration of the 

 fibres of Sharpey in decalcified bone. Sections are treated 

 with concentrated acetic acid until they become transparent, 

 and are then put for one quarter to one minute into a con- 

 centrated solution of indigo-carmine, then washed iu water 

 and mounted in glycerin or balsam. In successful prepara- 

 tions the fibres of Sharpey appear stained of a pale or dark 

 red, the remaining bone-substance blue. 



801. Cartilage (and Decalcified Bone). For an excellent 

 discussion (especially as regards staining) of the methods 

 that have been recently recommended for these objects, see 

 the exhaustive paper of SCHAPPEE in Zeit. f. wiss. Mik., v. 1, 

 1888, which gives in sufficient detail all the methods in ques- 

 tion. The following appear to be the best : 



RANVIER'S purpurin method. This has been given in detail 

 in 201. 



SCHAFFER'S safranin method. This method is due in its 

 principle to BOUMA (Centralb.f. d. med. Wiss., 1883, p. 866). 

 I give it in the form to which it has been brought by the 

 careful study of Schaffer (Zeit. f. wiss. Mik., v. 1, 1888, p. 17) . 

 Sections of bone decalcified with nitric acid (chromic acid 

 may be used, but the stain will be less brilliantly contrasted) 

 are stained for half an hour to one hour in 0*05 per cent, 

 aqueous solution of safranin, washed with water, put for two 

 or three hours in 0*1 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- 



