T. TADOKORO. 
of potassium iodide and 1.3 parts of iodin are dissolved in 10.5 parts of 
■water. The solution stains the cellulose reddish or bluish violet, the woody 
portion yellowish or brown and the wall, consisting of pectin substance, 
yellow. 
2. Congo red. It is easily soluble in water and stains the cellulose 
red. 
3. Safranin solution. A saturated safranin solution in alcohol is mixed 
with the same volume of water. It stains the pectin compounds yellowish 
red. 
4. Ruthenium red. It stains the pectin compounds intensely red. 
5. Methylen blue. It stains the pectin compounds violet. 
6. Millon’s reagent. The equal quantities of mercury and nitric acid 
are mixed and diluted in the same volume of water. It stains protein brick- 
red in a short time. 
7. Ammonium copper oxide solution. The solution is prepared fresh by 
pouring the concentrated ammonia over the copper foil or powder and allow- 
ing to stand for a day. It dissolves the cellulose easily. 
8. Phloroglucin and hydrochloric acid. A few drops of pliloroglucin 
and concentrated hydrochloric. acid produces a red color on the cross section 
of the lignified cell-wall. 
9. Fehling’ s solution. Three solutions are prepared separatly, each 
containing 35 grams of copper sulphate, 173 grams of Seignette salt 
(potassium sodium tartarate) and 120 grams of caustic soda in a liter of water 
respectively. Equal volumes of the solutions are mixed and diluted with 2 
parts of water just before using. The sections are put into this solution and 
warmed over a flame until bubbles appear. 
10. Sudan III. Sudan III. is a good coloring matter for fat. It stains 
fat, wax and cutin red. 
11. Osmic acid. It stains fat and protein brown. 
12. Alcanna tincture. It is prepared after Guigard’s method in the 
following manner. 10 grams of alcanna were extracted with 30 c.c. of absolute 
alcohol. Evaporate the extract and treat the residue with 5 c.c. of acetic 
