Sperm oil is a waxy liquid obtained from

sperm whale The sperm whale or cachalot (''Physeter macrocephalus'') is the largest of the toothed whales and the largest toothed predator. It is the only living member of the genus ''Physeter'' and one of three extant species in the sperm whale famil ...

s. It is a clear, yellowish liquid with a very faint odor. Sperm oil has a different composition from common

whale oil Whale oil is oil obtained from the blubber of whales. Whale oil from the bowhead whale was sometimes known as train oil, which comes from the Dutch word ''traan'' ("tears, tear" or "drop"). Sperm oil, a special kind of oil obtained from the ...

, obtained from rendered

blubber Blubber is a thick layer of vascularized adipose tissue under the skin of all cetaceans, pinnipeds, penguins, and sirenians. Description Lipid-rich, collagen fiber-laced blubber comprises the hypodermis and covers the whole body, except for pa ...

. Although it is traditionally called an "oil", it is technically a liquid wax. It is composed of

wax ester A wax ester (WE) is an ester of a fatty acid and a fatty alcohol. Wax esters comprise the main components of three commercially important waxes: carnauba wax, candelilla wax, and beeswax.. Wax esters are formed by combining one fatty acid with o ...

s with a small proportion of

triglyceride A triglyceride (TG, triacylglycerol, TAG, or triacylglyceride) is an ester derived from glycerol and three fatty acids (from ''tri-'' and ''glyceride''). Triglycerides are the main constituents of body fat in humans and other vertebrates, as w ...

s, an

ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides ar ...

of an

unsaturated fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, f ...

, and a branched-chain fatty alcohol. ransmission Digest, Volume 26, No. 2, October 2006, "The Science of Synthetic Sperm Whale Oil"/ref> It is a natural

antioxidant Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricant ...

and heat-transfer agent. In the late-18th and early-19th centuries, sperm oil was prized as an illuminant for its bright, odorless flame and as a

lubricant A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...

for its low

viscosity The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the inte ...

and stability. It was supplanted in the late 19th century by less expensive alternatives such as

kerosene Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning "wax", and was regi ...

and

petroleum Petroleum, also known as crude oil, or simply oil, is a naturally occurring yellowish-black liquid mixture of mainly hydrocarbons, and is found in geological formations. The name ''petroleum'' covers both naturally occurring unprocessed crud ...

-based lubricants. With the 1987 international ban on whaling, sperm oil is no longer legally sold. The oil from

bottlenose whale ''Hyperoodon'' (or ''Hyperoödon'') is a genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes ...

s was sometimes called "Arctic sperm oil." It was cheaper than and inferior to true sperm oil.

Processing

Sperm whale head anatomy (transverse + sagittal)

After killing a sperm whale, the whalers would pull the carcass alongside the ship, cut off the cranium and haul it on deck, whereupon they would cut a hole in it and bail out the matter inside with a bucket. The primary source of sperm oil was the spermaceti organ and the junk (or "melon"), the organs that serve to focus and modulate the animal's vocalizations. The matter from these organs was stored in casks to be processed on land; sometimes it was boiled first to prevent it going rancid. The blubber also contained smaller proportions of spermaceti, which was obtained by boiling the blubber on the ship itself. On land, the casks of head-matter were allowed to chill during the winter, causing it to congeal into a spongy and viscous mass. The congealed matter was then loaded into wool sacks and placed in a press to squeeze out its liquid. This liquid was bottled and sold as "winter-strained sperm oil". This was the most valuable product: a lubricant that remained liquid in freezing winter temperatures. When spring came and the leftover solid matter melted a bit, the liquid was strained off and sold as "spring-strained sperm oil". In summer, the matter melted some more and the liquid was strained off to leave a fully solid wax. This wax, brown in color, was then bleached and sold as "spermaceti wax".Wilson Heflin (2004). ''Herman Melville's Whaling Years''. pg 232
/ref>

Chemistry

Sperm oil has a fairly low viscosity (roughly equal to

coconut oil frameless , right , alt = A cracked coconut and a bottle of coconut oil Coconut oil (or coconut butter) is an edible oil derived from the wick, meat, and milk of the coconut palm fruit. Coconut oil is a white solid fat; in warmer climates duri ...

). It retains its viscosity in high temperatures better than most oils. It does not tend to become rancid, dry out, or corrode metals. Sperm oil cannot be easily

hydrogenated Hydrogenation is a chemical reaction between molecular hydrogen (H2) and another compound or element, usually in the presence of a catalyst such as nickel, palladium or platinum. The process is commonly employed to reduce or saturate organic ...

, and thus could not be used to make soap or margarine. It is fairly resistant to oxidization.

Spermaceti Spermaceti is a waxy substance found in the head cavities of the sperm whale (and, in smaller quantities, in the oils of other whales). Spermaceti is created in the spermaceti organ inside the whale's head. This organ may contain as much as of ...

is a liquid wax, composed mostly of

s (chiefly

cetyl palmitate Hexadecyl hexadecanoate, also known as Cetyl palmitate, is the ester derived from hexadecanoic acid and hexadecanol. This white waxy solid is the primary constituent of spermaceti, the once highly prized wax found in the skull of sperm whales.Wi ...

) and a smaller proportion of

s, with

oleic acid Oleic acid is a fatty acid that occurs naturally in various animal and vegetable fats and oils. It is an odorless, colorless oil, although commercial samples may be yellowish. In chemical terms, oleic acid is classified as a monounsaturated omega ...

being the most common

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, fr ...

. The proportion of wax esters in the spermaceti organ increases with the age of the whale: 38-51% in calves, 58-87% in adult females, and 71-94% in adult males. The blubber oil of the whale is about 66% wax.William F. Perrin, Bernd Würsig, J. G. M. Thewissen (2002). ''Encyclopedia of Marine Mammals''. pg 1164 When cooled to below , the waxes in spermaceti begin to crystallize. Winter-strained sperm oil is roughly two-thirds wax esters and one third triglycerides. Most of the carbon chains are unsaturated, with 18:1 being the most common.Gayland F. Spencer (1978). ''Alkoxy-Acyl Combinations in the Wax Esters from Winterized Sperm Whale Oil by Gas Chromatography-Mass Spectrometry''
/ref> Unlike other toothed whales save the

Amazon river dolphin The Amazon river dolphin (''Inia geoffrensis''), also known as the boto, bufeo or pink river dolphin, is a species of toothed whale classified in the family Iniidae. Three subspecies are currently recognized: ''I. g. geoffrensis'' (Amazon river ...

, most of the carbon chains in the wax esters are relatively long (C₁₀-C₂₂).

Applications

Sperm oil was particularly prized as an illuminant in oil lamps, as it burned more brightly and cleanly than any other available oil and gave off no foul odor. It was replaced in the late-19th century by cheaper, more efficient

. In the US, sperm oil was used in cars as an additive to automatic transmission fluid until it was banned by the

Endangered Species Act The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...

. Prior to 1972, over of sperm whale oil was used annually in lubricants because of its exceptional lubricity and heat stability.Landis, Phil. ''Gears for the Transmission Rebuilding Industry''. Oxnard: Automatic Transmission Rebuilders Association, 2010. Print. In 1972, the sperm whale was listed as an Endangered Species. The following year, the US Congress amended the Endangered Species Act, outlawing the killing of whales and the use of their oil. The loss of sperm oil had a profound impact in the automotive industry, where for example, transmission failures rose from under 1 million in 1972 to over 8 million by 1975. Sperm oil was a popular lubricant. It worked well for fine, light machinery such as sewing machines and watches because it is thin, does not congeal or dry out and does not corrode metals. It was also used in heavy machinery such as locomotives and steam-powered looms because it can withstand high temperatures. In the late 20th century,

jojoba oil Jojoba oil is the liquid produced in the seed of the ''Simmondsia chinensis'' ( jojoba) plant, a shrub, which is native to southern Arizona, southern California, and northwestern Mexico. The oil makes up approximately 50% of the jojoba seed by w ...

was discovered to be a better substitute for high-friction applications because it is even more stable at high temperatures. This caused sperm oil's price to collapse to a tenth of its previous value. Because of its very low

freezing point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends ...

, sperm oil saw widespread use in the aerospace industry. Sperm oil was used to protect metals from rust. A coat of sperm oil provided a temporary protection for the metal components in firearms, because it did not dry out or gum up.William S. Brophy (1985)
''The Springfield 1903 Rifles''
pg 71. It was the basis of the original (but not current) Rust-Oleum.

Gallery

File:Grinding and pressing spermaceti.jpg, A spermaceti press File:Filling bottles with sperm oil.jpg, Strained sperm oil being bottled File:Spermaceti candle and oil.jpg, A spermaceti wax candle File:Sperm oil bottle.jpg File:Grand Ball Given by Whales (Vanity Fair, 1861).jpg, Sperm whales celebrate the discovery of new oil wells in Pennsylvania. The proliferation of mineral oils reduced the demand for their species' oil. (1861 cartoon from ''Vanity Fair'') File:Sperm oil jug.jpg

References

{{reflist, 30em Animal fats Whale products