Jl! rilA 



3 Auf., 1890, p. 22] fix in the dark.) If yon icixh to have 

 a q,md xtain ;///// carmine you should not put the objects into 

 alcoliul at all, fi'<u for a second, until they have been stained. 

 V<ii inav stain i-ither with carmine or liaematoxylin, as 

 well as with tar colours. 



Biclir>mut' ol.j.'cts liave an ugly yellow colour which cannot be re- 

 .l l.y mere soaking in water. It is said that it can be removed by 

 washing for a lV\v minutes in a 1 per cent, solution of chloral hydrate. 



Prof. GILSON writes me that alcoholic solution of sulphurous anhy- 

 dride (SO.j) is very convenient for the rapid decoloration of bichromate 

 <>l.jiTt>. A few drops suffice. See also 37, and " Bleaching." 



To facilitate staining with haematoxylin, WOLFF (Zeit. wiss. Mik., xv, 

 .'.. l^'.'i*. p. 311) first stains in Boehmer's hsematoxylin for twenty-four 

 hours, and then for a few minutes in the same haematoxylin to which 

 has been added 1 drop per watch-glassful of 5 per cent, solution of 

 oxalic acid. 



The simple aqueous solution of bichromate is hardly to be 

 recommended as a fixing agent, because not only does it not 

 preserve nuclei properly, but also because it penetrates very 

 slowly. The first of these defects may be overcome entirely, 

 the second to some extent by addition of acetic acid ; whence 

 the liquid of TELLYESNICZKY, next . 



52. Acetic Bichromate (TELLYESNICZKY, Arch. mil-. An at., lii, 

 1889, p. 242) 



Bichromate ..... 3 grms. 



Glacial acetic acid . . . . 5 c.c. 



Water ...... 100 



Smaller objects to remain in the fluid for one or two days, 

 larger ones longer. Wash well in plenty of water, and pass 

 through alcohols of increasing strength, beginning with 15 

 per cent. 



Mixtures of bichromate with osniic acid have been given above, 43 

 and 44. 



53. MULLER'S Solution.- 



Bichromate of potash . . . 2-2 J parts. 



Sulphate of soda .... 1 part. 



Water ...... 100 parts. 



The duration of the reaction is about the same as with 

 the simple solution of chromic salt. 



