uble in cold water, and only slightly dissolved by
boiling water. The higher acids of the series are solid, and are
completely insoluble in water. All these acids are soluble in warm
alcohol, and on being heated with solid caustic alkali undergo no
change.

II. _Oleic Series:_--

--------------------------------------------------------------------------
Acid. | Formula. | Melting | Found in
| | Point, |
| | deg.C. |
--------------------------------------------------------------------------
Tiglic | C_{4}H_{7}COOH | 64.5 | Croton oil.
--------------------------------------------------------------------------
Moringic | C_{14}H_{27}COOH | 0 | Ben oil.
--------------------------------------------------------------------------
Physetoleic | C_{15}H_{29}COOH | 30 | Sperm oil.
--------------------------------------------------------------------------
Hypogaeic | C_{15}H_{29}COOH | 33 | Arachis and maize oils.
--------------------------------------------------------------------------
Oleic | C_{17}H_{33}COOH | 14 | Most oils and fats.
--------------------------------------------------------------------------
Rapic | C_{17}H_{33}COOH | ... | Rape oil.
--------------------------------------------------------------------------
Doeglic | C_{18}H_{35}COOH | ... | Bottle-nose oil.
--------------------------------------------------------------------------
Erucic | C_{21}H_{41}COOH | 34 | Mustard oils, marine animal
| | | oils, rape oil.
--------------------------------------------------------------------------

The unsaturated nature of these acids renders their behaviour with
various reagents entirely different from that of the preceding series.
Thus, they readily combine with bromine or iodine to form addition
compounds, and the lower members of the series are at once reduced, on
treatment with sodium amalgam in alkaline solution, to the corresponding
saturated acids of Series I. Unfortunately, this reaction does not apply
to the higher acids such as oleic acid, but as the conversion of the
latter into solid acids is a matter of some technical importance from
the point of view of the candle-maker, a number of attempts have been
made to effect this by other methods.

De Wilde and Reychler have shown that by heating o