The Abernethy biscuit was invented by Dr John Abernethy, a Scottish doctor, as a digestive improver and hence aid to health.

Dr Abernethy believed that most diseases were due to disorders in digestion. In creating his biscuit, Dr Abernethy was following in the footsteps of other medical practitioners, including Dr. William Oliver

William Oliver (physician)

William Oliver was an English physician and philanthropist, and inventor of the Bath Oliver. He was born at Ludgvan, Cornwall, and baptised on 27 August 1695, described as the son of John Oliver. His family, originally seated at Trevarnoe in Sithney, resided afterwards in Ludgvan, and the estate...

 of Bath, Somerset (invented the Bath Oliver

Bath Oliver

A Bath Oliver is a hard, dry biscuit or cracker made from flour, butter, yeast and milk; often eaten with cheese. It was invented by a Dr William Oliver of Bath, Somerset around 1750, giving the biscuit its name....

), and American preacher cum nutrition guru Sylvester Graham

Sylvester Graham

The Reverend Sylvester Graham was an American dietary reformer. He was born in Suffield, Connecticut as the 17th child of Reverend John Graham. Sylvester Graham was ordained in 1826 as a Presbyterian minister. He entered Amherst College in 1823 but did not graduate...

 (invented the Graham cracker

Graham cracker

The graham cracker was developed in 1829 in Bound Brook, New Jersey, by Presbyterian minister Rev. Sylvester Graham. The true graham cracker is made with graham flour, a combination of fine-ground white flour and coarse-ground wheat bran and germ. Graham crackers are often used for making s'mores...

).

The Abernethy biscuit is an adaptation of the plain captain’s biscuit or hardtack

Hardtack

Hardtack is a simple type of cracker or biscuit, made from flour, water, and sometimes salt. Inexpensive and long-lasting, it was and is used for sustenance in the absence of perishable foods, commonly during long sea voyages and military campaigns. The name derives from the British sailor slang...

, with the added ingredients of sugar

Sugar

Sugar is a class of edible crystalline carbohydrates, mainly sucrose, lactose, and fructose, characterized by a sweet flavor.Sucrose in its refined form primarily comes from sugar cane and sugar beet...

 (for energy), and caraway seeds because of their reputation for being beneficial in digestive disorders. The biscuit is a cross between an all butter biscuit and a shortcake

Shortcake

Shortcake is a sweet biscuit .Shortcake is typically made with flour, sugar, baking powder or soda, salt, butter, milk or cream, and sometimes eggs. The dry ingredients are blended, and then the butter is cut in and mixed until the mixture resembles cornmeal...

, raising through use of ammonium bicarbonate

Ammonium bicarbonate

Ammonium bicarbonate, a compound with formulaNH4, also called bicarbonate of ammonia, ammonium hydrogen carbonate, hartshorn, AmBic or powdered baking ammonia, is the bicarbonate salt of ammonia....

.

Today, Abernethy biscuits are made in Edinburgh

Edinburgh

Edinburgh is the capital city of Scotland, the second largest city in Scotland, and the eighth most populous in the United Kingdom. The City of Edinburgh Council governs one of Scotland's 32 local government council areas. The council area includes urban Edinburgh and a rural area...

 by Simmers (Estd 1888). Made in a nut-free bakery, the biscuits have no artificial colourings, flavourings or preservatives, and no genetically modified ingredients. The biscuits are suitable for vegetarians and vegans.