: GUMS AND RESINS EXUDED BY QUEENSLAND PLANTS 
_ CHEMICALLY AND TECHNOLOGICALLY DESCRIBED. 
By Dr, JOSEPH LAUTERER, M.D. 
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The inspissated juices of living plants exuded from wounds on 
the surface or from the inside of disintegrated tissues, mostly dried up 
by exposure to air, may for practical purposes be classified into four 
groups— 
1. Resins, unaltered by and insoluble in water. 
2. Gums, swelling up in or entirely dissolved by water. 
8. Gum-resins, composed in the fresh state of an inspissated 
emulsion of a resinous body insoluble in water, derived from an essential 
oil, and held in suspension by a watery solution of a kind of arabin. 
_ 4. Tan-resins, partly soluble in water, leaving an insoluble residue 
which is derived from a tannin, and which residue is soluble in caustic 
_ Potash and sometimes in alcohol. 
A.—RESINS. 
N I Resins soluble in strong caustic potash with intense colouration. 
ot derived from an essential oil, but from a tannin. 
L Alcoholic solution reddish yellow, getting golden yellow on 
dition of caustic potash. Xanthorrhea arborea, R. Br. 
2. Alcoholic solution pure yellow, getting greenish on.addition of 
ay pilstic potash. Xanthorrhea hastilis, R. Br. : 
disso} Resins not dissolved entirely by caustic potash and, if 
ved, showing only a slight colouration. ; 
* -7ying up only after some days or weeks (soft resins). 
(4) Fresh resin destitute of a pungent aromatic taste and smell, 
not reminding of turpentine. Ailanthus imberbiflora, var. 
- Bail 
acartneyt, Bail. : 
() Taste and smell of the fresh resin, reminding of turpentine 
or lavender or nutmegs. ~ ; 
(aa) Ferric salt gives colour reaction with fresh alcoholic 
Solution of the resin. : : ; 
(1) Ferric salt stains the fresh alcoholic resin solution 
green. (Smell of lavender.) “Tacamahac,” from Calo- 
phyllum inophyllum, L. : : : 
(2) Ferrie salt stains the alcoholic resin solution violet, 
turning into Indian red and brown. (Smell of turpen- 
tine.) Syncarpia Hillii, Bail. : 
(0) RE ark colour reaction with fresh alcoholic 
resin solution. ‘ . 
1) Caustic potash without reaction on the alcoholic resin 
olution ; r cent. of a colourless essential = 
smelling like oil of Strasburg turpentine are distille 
or at 165° ©., and a colourless a resin is left in 
€ still. Canarium Muelleri, Bail. ; 
(2) Oaustic potash givesa yellow colouration to the alcoholic 
resin solution. Pittosporum undulatum, Vent. 
