SOURCE AND AVERAGE ANALYTICAL CHARACTERISTICS OF THE PRINCIPAL DRYING OILS

Oil
Source
Per cent of oil content
Specific gravity at I5°C.
Refractive index
Saponi-fication number
Acid number
Iodine number
Per cent of non-saponi-fiable matter

Candlenut
Aleurites moluccana
—
0.925
1.470/40°
193
2
164
0.5-1.0

Hempseed
Cannabis sativa
—
0.927
1.474/40°
191
0.45
148
I.o8

Linseed
Linum usitafissfmutn
35~40
0.932-0.941
1.484/15°
190-195
1-8
170-195
0.5-1.0

Perilla
Perilla ocimoides
3*
o-937
1.487/40°
*93
4.3
190-205
—

Poppy-seed
Papaver somniferum
45
0.924-0.926
1-477/15°
190-195
I-IO
140-158
0.5

Soya bean
Glycine hispidu
18
0.924-0.926
1.468/40°
190-192
o-5
126-135
0.5

Sunflower
Helianthus annuus
5°
0.924-0.926
L473/250
188-193
6-12
125-140
0.3-0.5

Tung
Akurites cordata
50
0.936-0.943
1.522/15°
191-196
O-I2
160-175
0.5-1.0

Walnut
Juglans regia
63-65
0.924-0.927
1.480/15°
190-197
2.5
140-150
0.5-1.0

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§

02

THE DRYING CURVES OF LINSEED OIL

~\s\

lO DAYS

£O D/WS

30 OKY6

6O PAY.5

d

The weight increase of drying linseed oil, as a result of combination with oxygen is shown graphically. In these curves which
have been adapted from A. Eibner, Vber Fette 6/e, p. 30, table I, per cent increase in weight is plotted against drying time
in days. Curve a shows it for linseed oil, cold-pressed and prepared as a film in the dark and weighed in red light. Curve
b is for the same oil prepared and dried in diffuse daylight. I = point of initial set; 2 = tacky stage; 3 = tack-free dryness.