Weigh out

Methylene-blue 1.5 grammes

Place in a stoppered bottle of 150 c.c. capacity and add

Alcohol, 90 per cent 100.0 c.c.

Allow the alcohol to remain in contact with the dye for two hours, shaking vigourously every few minutes. Filter.

3. _Carbolic Methylene-blue_ (Kuehne).

Weigh out

Methylene-blue 1.5 grammes Carbolic acid 5.0 grammes

and dissolve in

Distilled water 100.0 c.c.

and add

Absolute alcohol 10.0 c.c.

Filter.

4. _Alkaline Methylene-blue_ (Loeffler).

Measure out and mix

Methylene-blue, saturated alcoholic solution 30.0 c.c.

Caustic potash, 0.1 per cent. aqueous solution 100.0 c.c.

Filter.

~Gentian Violet.~--

5. _Saturated Aqueous Solution._

Weigh out

Gentian violet 2.25 grammes

and proceed as in preparing the corresponding solution of methylene-blue.

6. _Saturated Alcoholic Solution._

Weigh out

Gentian violet 5.0 grammes

and proceed as in preparing the corresponding solution of methylene-blue.

7. _Carbolic Gentian Violet_ (Nicolle).

Measure out and mix

Gentian violet, saturated alcoholic solution 10.0 c.c.

Carbolic acid, 1 per cent. aqueous solution 100.0 c.c.

Filter.

8. _Anilin Water Solution_ (Koch-Ehrlich).

Measure out

Distilled water 100 c.c.

Add anilin oil drop by drop (shaking well after the addition of each drop) until the solution is opaque.

Filter until clear.

and add

Absolute alcohol 10 c.c.

Saturated alcoholic solution gentian violet 11 c.c.

Filter.

NOTE.--This solution will not keep longer than 14 days.

~Thionine Blue (or Lauth's Violet).~--

9. _Carbolic Thionine Blue_ (Nicolle).

Weigh out

Thionine blue 1.0 gramme Carbolic acid 2.5 grammes

and dissolve in

Distilled water 100.0 c.c.

Filter.

Before use dilute with equal quant.i.ty of distilled water and again filter.

~Fuchsin (Basic).~--