FORMULAS FOR REAGENTS 395 



one. The certified American safranins give good results whether dis- 

 solved in water, anilin water, 50 per cent alcohol, or stronger alcohols. 



Safranin 1 g- 



Alcohol, 50 per cent 100 c.c. 



or 



Safranin 1 g. 



Water 100 c.c. 



or 



Safranin 1 g. 



Anilin (3 per cent anilin oil in water) 100 c.c. 



Gentian violet. — 



Gentian violet 1 g. 



95 per cent alcohol 20 c.c. 



Water SO c.c. 



Anilin oil 3 c.c. 



A 1 per cent solution in water keeps better, but does not stain the 

 achromatic structures of mitotic figures so well. 



A solution in clove oil is made by dissolving 1 g. gentian violet in 

 100 c.c. of absolute alcohol, and adding 100 c.c. of clove oil. Let the 

 alcohol evaporate until there is practically a clove oil solution. 



Crystal violet. — 



This is a very pure violet. It can be substituted for gentian violet in 

 all formulas. 



Methyl violet (for flagella). — 



20 per cent aqueous solution of tannin 10 c.c. 



Cold saturated solution of ferrous sulphate 5 c.c. 



Saturated solution of methyl violet (or fuchsin) . . 1 c.c. 



Add the sulphate to the tannin and then add the violet. 

 For Bacillus tijphosis, add to the mixture a few drops of caustic 

 soda. For Bacillus suhtilis, add 30 drops. 



Pyoktanin. — 



This is sold by E. Merck, in Darmstadt, Germany. 



Dissolve 1 g. of pyoktanin in 30 c.c. of water. 



Orange G. — 



Orange G 1 g. 



Water 100 c.c. 



For most purposes a solution in clove oil is preferable. It is easier 

 to get a solution by dissolving 0.1 g. of orange in 100 c.c. of absolute 



