122 COMBINATION STAINS. 



better in general be avoided, and the picric acid only added 

 to the pure alcohol used after washing out. 



Combinations having Carmine for a Primary Stain. 



225a. Picro- Carmine. Picro-carmine is a double stain, if care 

 be taken not to wash out the picrin beyond the point desired. 

 And it is one of the best of double stains. 



226. Borax- Carmine and Picro-Carmine. A very beautiful 

 and precise double stain may be obtained by means of this 

 combination. I add to a watch-glassful of Grenacher's alco- 

 holic borax-carmine a few drops of picro-carmine. 



The mixture will precipitate in the course of a few hours, 

 but the stain will be obtained nevertheless. 

 BAUMGARTEN'S borax-picro-carmine ( 163). 



227. Carmine and Picric Acid. This combination has been 

 already sufficiently explained above (see 225a). 



LEGAL' s alum-carmine and picric-acid mixture ( 152). 



228. Orth's Picro-Lithium Carmine. A mixture of one part of 

 lithium-carmine (ante, 153) and two or three parts of satu- 

 rated aqueous solution of picric acid. If the mixture should 

 over-stain either in yellow or in red, add a little of the other 

 colour. Wash out with acidulated (HC1) alcohol, as for 

 simple lithium- carmine. 



229. Setter's Carmine followed by Indigo-carmine (Am. Quart. 

 Mic. Journ., i, 1879, p. 220; Journ. Roy. Hie. Soc., ii, 1879, 

 p. 613). Stain in Woodward's borax-carmine ( 159), wash 

 out in HC1 one part, alcohol four parts, until the sections 

 assume a bright rose colour (which appears in a few seconds). 

 Wash the acid out of the sections, and stain for six to eighteen 

 hours in a mixture of two drops of sulpbindigotate of soda 

 solution with one ounce of 95 per cent, alcohol. The mixture 

 should be filtered before using ( 190). 



Nuclei red, formed material slightly tinged with blue. 



It is obvious that this method may be modified, in most 

 cases with advantage, by using Grenadier's alcoholic borax- 

 carmine or HC1 (alcoholic) carmine, or any similar carmine 

 stain, instead of the aqueous solution of Woodward. Heneage 

 Gibbes uses the borax-carmine quoted under his name ( 160). 



