The Collaborative International Dictionary of English v.0.48:
Hartshorn \Harts"horn`\ (-h[^o]rn`), n.
1. The horn or antler of the hart, or male red deer.
2. Spirits of hartshorn (see below); volatile salts.
Hartshorn plantain (Bot.), an annual species of plantain
(Plantago Coronopus); -- called also buck's-horn.
Hartshorn shavings, originally taken from the horns of
harts, are now obtained chiefly by planing down the bones
of calves. They afford a kind of jelly. --Hebert.
Salt of hartshorn (Chem.), an impure solid carbonate of
ammonia, obtained by the destructive distillation of
hartshorn, or any kind of bone; volatile salts. --Brande &
Spirits of hartshorn (Chem.), a solution of ammonia in
water; -- so called because formerly obtained from
hartshorn shavings by destructive distillation. Similar
ammoniacal solutions from other sources have received the