132 HJKMATEI'N AND OTHER OEGANIC STAINS. 



Dissolve 5 grms. of saffron in 15 c.c. of absolute alcohol; allow the 

 solution to settle for a few days, filter, and dilute with one half of water. 

 After staining wash out to the desired degree with 80 per cent, alcohol, then 

 dehydrate with absolute alcohol, and mount in balsam. 



205. LEVEN (The Microscope, ix, 1889, p. 88 ; Journ. Roy. Mic. Soc., 

 1889, p. 467) has been using saffron for the study of the regeneration of 

 muscle. He stains in a solution containing saffron 1 part, absolute alcohol 

 100 parts, water 200, and washes out in acidulated alcohol (0'5 per cent. 

 HC1). Karyokinetic figures dark red, muscle nuclei pale with dark red 

 nucleoli. Leucocytes stain strongly. 



206. Orchella (Orseille) (WEDL, Arch. f. path. Anat., Ixxiv, 

 p. 143; Journ. Roy. Mic. Soc., ii, 1879: for an account of 

 this substance vide COOLEY'S Cyclopsedia,subvoce "Archil"). 

 French orchella extract, from which the excess of ammonia 

 has been removed by gentle warming in a sand-bath, is poured 

 into a mixture of absolute alcohol 20 c.c., acetic acid (concen- 

 trated, of 1*070 sp. gr.) 5 c.c., and water 40 c.c., until a 

 saturated dark red stain is obtained, which must then be 

 filtered once or twice. Sections are washed with water, 

 drained, and treated with the stain. Mount in levulose. A 

 protoplasmic stain, nuclei remaining colourless. Connective- 

 tissue cells stain deeply, the intercellular substance less 

 deeply. Epithelia, if horny or calcareous, are not stained. 

 The basic substance of bone and teeth take the stain, and so 

 do ganglion-cells and their processes. 



This colour ought to be useful for double-staining. FOL 

 (Lehrb., p. 192) advises staining for an hour in Wedl's solu- 

 tion, then rinsing with alcohol, and staining in a complemen- 

 tary stain. 



207. Orcein (ISRAEL, Virchow's Archiv, cv, 1886, p. 169; Journ. Roy. 

 Mic. Soc., 1887, p. 514). Orcein (not " orcin," as erroneously printed in 

 the last edition of this work) is a vegetable dye obtained from tinctorial 

 lichens, which unites in itself the staining properties of the basic and acid 

 stains, and also the combination of two contrast colours. Israel stains sec- 

 tions in a saturated acetic acid solution, washes in distilled water, and passes 

 rapidly through absolute alcohol to thick cedar oil, in which the preparations 

 remain definitively mounted. Nuclei blue, protoplasm red. 



For the specific staining of elastic tissue by means of this reagent, a 

 subject which has been carefully worked out by TANZER and UNNA, see the 

 paragraphs on the Connective Tissues in Part II. 



208. Kernschwarz (PLAINER, Zeit.f. wiss. Mik., iv, 3, 1887, 

 p. 350; Journ. Roy. Mic. Soc., 1888, p. 675). Kernschwarz 



