various oils used as cloth oils
which the author has had occasion to analyse.

1. 2. 3. 4.
Specific gravity at 60 deg. F. 0.9031 0.9091 0.6909 0.8904
Free fatty acid 55.02 64.42 51.52 68.05
Unsaponifiable oil 34.56 9.95 32.80 9.52
Saponifiable oil 10.32 25.32 15.68 12.43
------ ------ ------ ------
100.00 100.00 100.00 100.00

Nos. 1 and 2 are prepared from Yorkshire grease. The unsaponifiable
matter in these is purely natural, it will be seen it varies within
wide limits. Nos. 3 and 4 are made from the oleic acid of the candle
factories, and the unsaponifiable matter is due to their containing
mineral oil which has been added to them.

So far as regards the object for which the wool is oiled, the mineral
oils will answer almost as well as the fatty oils and with most (p. 027)
satisfactory results from an economical point of view, for they are
much cheaper. But this is not the only point to be considered. The oil
has to be got out of the wool before the latter can be dyed. Now while
the fatty oils can be easily removed, by treatment with soap, and they
can be recovered along with the fat of the soap, mineral oils cannot
be entirely removed from the wool, what remains in will interfere very
much with the satisfactory dyeing of the wool, and what is got out
finding its way into the covered wool grease, spoils this for soap
making and other uses, so that on the whole what is gained in lessened
cost of oiling is lost by the increased liability to defects in dyeing
and consequently depreciation in value of the wool, and to decrease in
value of the recovered grease.

The amount of oil used varies from 7 per cent. with the best wools to
15 per cent. with shoddy wools. The scouring agents generally used are
the same as those used in loose wool scouring, namely, carbonate of
soda for coarse woollen yarns, soap and soda for medium yarns, and
soap and ammonia for fine yarns. Prior to treating the yarns it is
best to allow them to steep in hot water at about 170 deg. F. for twenty
minutes, then to allow them to cool. The actual scouring is often done
in large wooden tubs, across which rods can be put on which to hang
the hanks of yarn, and in which are placed steam pipes for heating up
the bath. The best temperature to tre