500 APPENDIX. 



Bichromate of potash ... 3 ounces. 3.t 



Sulphuric acid . . . .3 fluid ounces. ^>; 



Water . 25 



Wash with water. The slides may be simply drained dry ; 

 the covers may be wiped dry with a linen rag. 



Slides and covers that have been used for mounting either 

 with balsam or a water medium are treated as follows : The^ 

 covers are pushed into a mixture of equal parts of alcohol 

 and hydrochloric acid, and after a few days are put into the 

 bichromate solution and treated like new ones. The slides 

 are scraped free of the mounting medium with a knife and 

 put directly into the bichromate solution. 



FOL (Lehrb., p. 132) recommends either a solution con- 

 taining 3 parts of bichromate, 3 of sulphuric acid, *nd 40 of 

 water ; or simply dilute nitric acid. 



G-ARBINI (Manuals, p. 31) puts slides for a day into 10 per 

 cent, sulphuric acid, then washes, first with water and then 

 with alcohol. 



BEHEENS (Zeit. f. wiss. Mik., 1885, p. 55) treats slides 

 first with concentrated nitric acid, then with water, alcohol, 

 and ether. 



JAMES (Journ. Roy. Mic. Soc., 1886, p. 548) treats used 

 slides with a mixture of equal parts of benzin, spirit of 

 turpentine, and alcohol. 



KNAUER (Centralbl. f. Bakt., x, 1891, p. 8; Zeit. f. wiss. 

 Mik., ix, 2, 1892, p. 187 ; Journ. Roy. Mic. Soc., 1891, p. 833) 

 recommends boiling for twenty or thirty minutes in 10 per 

 cent, lysol solution, then rinsing with cold tap water till 

 clear. 



NIAS (Journ., pag. cit.) finds it is sufficient to boil with 

 washing soda, and rinse. 



ZIELINA (Zeit. f. wiss. Mik., xiv, 1897, p. 368) puts used 

 slides for some days into water, and scrapes off the balsam 

 with a piece of wood. He treats new slides or covers for a 

 few minutes with glacial acetic acid, washes, and dries with 

 a cloth. 



889. Re-staining Old Mounts (HENNEGUY, from the last edition 

 of the Traitedes Methodes techniques de I'Anat. microsco pique, 

 LEE et HENNEOTY). It is probably not generally known that 

 balsam mounts the stain of which has faded, or which it may 



