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ON THE CHEMISTRY OF AUSTRALIAN PRODUCTS. 201 
becomes partly soluble in hot water. By oxidation with nitric 
acid it yields oxalic acid and no mucic acid, and as it also gives no 
precipitate with lead acetate it is not a gum. 
Analyses give 43:7 and 43-07 per cent. C, and 6°6 and 6:4 per 
cent. H, agreeing with the formula C,H, O; Like starch, lerp 
amylum rotates the plane of polarization to the right ; and on 
digestion with dilute sulphuric acid, forms a substance analogous to 
n. 
Evcatyptus MANNA. Johnston. (Mem. Chem. Soc. L, 159; 
Watt’s Dict., II, 601.) 
This manna is a loose white granular mass exuded by some of the 
Eucalypti and contains a erystallizable sugar melitose, which 
when air-dried has the formula C,, H., O,, H, O. 
Metirosr. Berthelot. (Ann. Ch. Phys. [3], XLVI, ye Chimie 
i I, 1869. 
This substance is extracted from Australian manna by water, 
and crystallizes in very thin needles, which are slightly sweet. The 
crystals are hydrated, and contain C,, Hx, O, 3 H_ O; they lose 2 
re 
soluble in boiling water and in nine parts of cold, and are also 
soluble in alcohol, and the latter solution yields small well 
developed crystals. The aqueous solution is dextrorotatory, and 
turns the plane of polarization for the transition tint a = + 102°. 
Dilute sulphuric acid resolves it into a fermentable sugar and 
nhon-fermentable eucalyn 
C12 Hoe O11 + He O = Ce His Oc + Co His Oc 
: elitose glucose eucalyn 
Melitose ferments with yeast, being first resolved into glucose 
y alcohol and carbon 
dioxide that glucose does. It does not {reduce alkaline cupric 
Solutions, and is unaltered by boiling dilute alkalies or baryta water. 
] 
Nitric acid oxidizes it, yielding mucic and oxalic acids. 
of sulphuric acid. It is dextrorotary a = + 
substance, Sulphuric acid or strong hydrochloric acid destroys it 
at 100°, and boiling baryta water colours it strongly. It reduces 
Fehling’s copper solution. 
. 
- to consist principally of a hydrocarbon analogous to oil of turpen- 
ae ydrocar . s 
ae and resembling it in odour. Ananalysis gave numbers agreeing 
