DIPHTHE RTA. 139 
Hunts Stain, 
(a) Prepare films as usual. 
(6) Stain in aqueous methylene-blue for one 
minute. 
(c) Wash in water and dry. 
(d) Treat with a Io per cent. solution of tannic 
acid for one minute. 
(e) Wash in water and dry. 
(/) Stain in aqueous methyl-orange for one 
minute. 
(g) Wash, dry, and mount. 
Neisser’s Stain. 
(a) Prepare solution A as follows: 
Methylene-blue, I gm.; 
Alcohol (95 per cent.), 20 €.C. 
Dissolve and add 
Acetic acid, 50 ¢.C.3 
Water, 950 c.c. 
(4) Prepare solution B as follows: 
Bismarck-brown, 2gm.; 
Boiling water, IOOO ¢.¢. 
(c) Treat films with solution A for one to three 
seconds. 
(@) Wash in water. 
(e) ‘Treat with solution B for three to five seconds. 
(f) Wash, dry, and mount. 
11. Test the virulence of the diphtheria organism 
isolated as follows : 
