Harts' horns, are the horns of the male red deer

Red Deer

The red deer is one of the largest deer species. Depending on taxonomy, the red deer inhabits most of Europe, the Caucasus Mountains region, Asia Minor, parts of western Asia, and central Asia. It also inhabits the Atlas Mountains region between Morocco and Tunisia in northwestern Africa, being...

. Various substances were made from the shavings of the animals' horns.

The oil of hartshorn is a crude animal oil obtained from the destructive distillation of the deers' bones or horns.

The salt of hartshorn actually refers to two distinct substances, sal ammoniac (ammonium chloride

Ammonium chloride

Ammonium chloride NH4Cl is an inorganic compound with the formula NH4Cl. It is a white crystalline salt that is highly soluble in water. Solutions of ammonium chloride are mildly acidic. Sal ammoniac is a name of natural, mineralogical form of ammonium chloride...

), and ammonium carbonate

Ammonium carbonate

Ammonium carbonate is a commercial salt with the chemical formula 2CO3. It is used when crushed as a smelling salt. It can be crushed when needed in order to revive someone who has fainted...

, which have been obtained from oil of hartshorn by dry distillation

Dry distillation

Dry distillation is the heating of solid materials to produce gaseous products . The method may or may not involve pyrolysis/thermolysis. The products are condensed and collected. This method usually requires higher temperatures than classical distillation. The method has been used to obtain...

.

The spirit of hartshorn (or spirits of hartshorn

Spirits of Hartshorn

Spirits of Hartshorn was a name signifying originally the ammoniacal liquor obtained by thedistillation of horn shavings, afterwards applied to the partially purified similar products of the action of heat on nitrogenous animal matter generally, and now popularly used to designate the aqueous...

) is an aqueous solution of ammonia

Ammonia

Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

. Originally this term was applied to a solution manufactured from the hooves and horns of the red deer, as well as those of some other animals. The aqueous solution was a colorless and pungent, consisting of about 28.5 percent ammonia. It was used chiefly as a detergent

Detergent

A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...

, for removing stains and extracting certain vegetable coloring agents, and in the manufacture of ammonium salts. Later the term was applied to the partially purified similar products of the action of heat on nitrogenous animal matter generally, and finally the term was applied to any aqueous solution of ammonia.

Medicine

Hartshorn jelly or a decoction of burnt hartshorn in water was used to treat diarrhoea. The coal of hartshorn, called calcinated

Calcination

Calcination is a thermal treatment process applied to ores and other solid materials to bring about a thermal decomposition, phase transition, or removal of a volatile fraction. The calcination process normally takes place at temperatures below the melting point of the product materials...

 hartshorn, was used as an absorbent, as well as in the treatment of dysentery

Dysentery

Dysentery is an inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhea containing mucus and/or blood in the faeces with fever and abdominal pain. If left untreated, dysentery can be fatal.There are differences between dysentery and normal bloody diarrhoea...

. Salt of hartshorn (ammonium carbonate

Ammonium carbonate

Ammonium carbonate is a commercial salt with the chemical formula 2CO3. It is used when crushed as a smelling salt. It can be crushed when needed in order to revive someone who has fainted...

) was used as a sudorific for treatment of fevers, and as a smelling salt. Hartshorn was used to treat insect bites, sunstroke, stye

Stye

An external stye or sty , also hordeolum , is an infection of the sebaceous glands of Zeis at the base of the eyelashes, or an infection of the apocrine sweat glands of Moll. External styes form on the outside of the lids and can be seen as small red bumps. Internal styes are infections of the...

, and snakebites.

Baking

Hartshorn salt (ammonium carbonate), also known simply as hartshorn, and baker's ammonia, was used as a leavening agent

Leavening agent

A leavening agent is any one of a number of substances used in doughs and batters that cause a foaming action which lightens and softens the finished product...

, in the baking of cookies and other edible treats. It was used mainly in the 17th and 18th centuries as a forerunner of baking powder

Baking powder

Baking powder is a dry chemical leavening agent used to increase the volume and lighten the texture of baked goods such as muffins, cakes, scones and American-style biscuits. Baking powder works by releasing carbon dioxide gas into a batter or dough through an acid-base reaction, causing bubbles in...

. ½ teaspoon of hartshorn can substitute for 1 teaspoon of baking powder. It is called for in old German and Scandinavian recipes and, though rarely used in modern times, may still be purchased as a baking ingredient. Hartshorn helps molded cookies such as Springerle

Springerle

Springerle is a type of German biscuit with an embossed design made by pressing a mold onto rolled dough and allowing the impression to dry before baking. This preserves the detail of the surface pattern. They are most commonly seen during the Christmas season.The name springerle means "little...

 to retain their intricate designs during baking. Cookies make with hartshorn can be kept for a long time without hardening. Use of hartshorn may turn some ingredients, such as sunflower seeds, green.

Ammonium carbonate is especially suited to thin, dry cookies and crackers. When heated, it releases ammonia and carbon dioxide gases, but no water. The absence of water allows cookies to cook and dry out more quickly, and thinner cookies allow the pungent ammonia to escape, rather than to remain trapped, as it would in a deeper mass. Other than the pungent ammonia smell that is produced when baking with ammonium carbonate, and the possibility of a slight ammonia taste remaining in the baked goods, is that the ammonia released during the baking process reacts with glucose and fructose to form intermediate molecules which in turn react with asparagine

Asparagine

Asparagine is one of the 20 most common natural amino acids on Earth. It has carboxamide as the side-chain's functional group. It is not an essential amino acid...

 (an amino acid found in nuts, seeds, and whole grains) to form acrylamide

Acrylamide

Acrylamide is a chemical compound with the chemical formula C3H5NO. Its IUPAC name is prop-2-enamide. It is a white odourless crystalline solid, soluble in water, ethanol, ether, and chloroform. Acrylamide is incompatible with acids, bases, oxidizing agents, iron, and iron salts...

, a carcinogen

Carcinogen

A carcinogen is any substance, radionuclide, or radiation that is an agent directly involved in causing cancer. This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes...

.