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REAGENTS. 
Chloral-Iodine Solution consists of a saturated aqueous 
solution of chloral, to which as much iodine is added 
as it will take up. 
Phloroglucin Solution, also known as “ Wiesner’s 
Reagent,” is a 0'5 to 2 per cent, alcoholic solution of 
phloroglucin, which is used in conjunction with hydro- 
chloric acid. 
Iron Solutions are aqueous or alcoholic solutions con- 
taining 5 to 20 per cent, of ferric acetate or ferric chlo- 
ride. The name “ Moeller’s Reagent ” is given to a 
solution of anhydrous ferric chloride in anhydrous 
ether. 
Copper-Acetate Solution is a 7 per cent, aqueous solu- 
tion of cupric acetate. 
Double Staining, or the use of two stains in the ex- 
amination of a specimen, furnishes not only a means 
of beautifying the specimen, but also has a certain 
diagnostic value. The following are some of the com- 
binations used : (a) aqueous solutions of carmine in 
connection with alcoholic solutions of iodine green ; 
(i b ) alcoholic solutions of hsematoxylin and safranin ; 
(c) solutions of eosin and methylene blue ; (d) solutions 
of fuchsin and methylene blue; (e) solutions of gentian 
violet and Bismarck brown. 
Special Reagents comprise all those substances which 
are employed in the morphological study of the cells, 
and include solutions of the alkalies (0T to 6 per 
cent.), solutions of the mineral acids, which may be 
weak or concentrated, and solutions of organic acids, 
as acetic and citric. 
Schulze’s Macerating Solution is prepared by adding 
crystals of potassium chlorate from time to time to a 
warm concentrated nitric acid. It is employed in the 
isolation of lignified cells. 
