1918] SAM PSON—ABSCISSION oe 51 
CELLULOSE.—(1) Chlorzinc iodide: blue color; (2) hydro- 
cellulose reaction: blue color with iodine after treatment with 75 
per cent sulphuric acid; (3) solubility: insoluble in dilute acids and 
alkalies, soluble in copper-oxide-ammonia; (4) crystallization: 
dissolve in copper-oxide-ammonia, wash with ammonia and water; 
colorless sphaero crystals or spiculate crystal clusters appear within 
the cells; (5) crystal reactions: insoluble in dilute acids and alkalies, 
soluble in copper-oxide-ammonia and sulphuric acid; blue color 
with chlorzinc iodide; (6) membranes of cellulose exhibit double 
refraction in polarized light. 
PECTIC COMPOUNDS IN GENERAL.—(r1) Ruthenium red: red color; 
(2) methylene blue: violet color; (3) membranes of pectic 
compounds do not exhibit double refraction in polarized light. 
PEcTOSE.—(1) Insoluble in copper-oxide-ammonia, dilute 
alkalies, ammonia, and alkali carbonates; (2) converted into pectic 
acid and pectin when gently heated with 2 per cent hydrochloric 
acid for 30 minutes. These latter substances are readily dissolved 
by 2 per cent potassium hydroxide or 5 per cent sodium carbonate, 
leaving the cellulose membrane intact. 
Prectic acim.—(1) Soluble in dilute alkalies, ammonia, and 
alkali carbonates; (2) insoluble in water. 
Prectin.—Soluble in water. 
CALCIUM PECTATE.—(1) Hydrolyzed by 2 per cent hydrochloric 
acid: calcium chloride is formed and pectic acid set free; (2) 3 per 
cent oxalic acid or ammonium oxalate: calcium oxalate crystals 
are formed, pectic acid set free; (3) 5 per cent sulphuric acid: 
calcium sulphate crystals formed, pectic acid set free. 
Catcrum.—(1) Two per cent oxalic acid: calcium oxalate 
crystals; (2) 5 per cent sulphuric acid: calcium sulphate crystals. 
Licnin.—Phloroglucin-HCl reaction: red violet color. 
SUBERIN.—(1) Sudan III or Scharlach R: red color; (2) 
insoluble in copper-oxide-ammonia; (3) phellonic acid reaction. 
Fructose.—(r) Fluckiger’s reaction: yellowish-red precipitate 
of cuprous oxide at once without heating; (2) phenylhydrazine 
reaction: yellow osazone crystals formed in 6-8 hours; (3) methyl- 
phenylhydrazine reaction: insoluble osazone; crystals formed in 15 
minutes if preparation is heated, after 24 hours at room temperature. 
