496 MATERIA MEDICA 



HOP. — Ilumulus. A decoction of hops is a good stomacliic 

 bitter and anodyne, possessing a weak narcotic quality. It 

 forms also a good anodyne and discutient fomentation. 



HORSE-liADISH. — Artnorocia. The rootof horse-radisli, 

 when fresh, is a powerful stimulant. All its virtues may be ex- 

 tracted by distilling the root with water or spirit; in which 

 state it may be kept a long time without losing its strength. It 

 is said to possess also a diuretic and diaphoi'etic quality. Its 

 acrimony is destroyed by boiling ; it is therefore given either as 

 an infusion, or beaten into a mass with flour, as a ball. If beaten 

 into a mass, and formed into a paste, with flour of mustard and 

 water, it is capable of blistei'ing the skin. 



HYDRAGOGUES. This appellation is given to those 

 medicines that act on the kidneys, increasing the secretion of 

 urine. The real derivation of the word, however, would imply 

 anything which produced an evacuation of liquids, and therefore 

 the epithet may be and is very justly applied to drastic pur- 

 gatives, which induce liquid motions. 



HYDPvARGYHUM. Mercury: which see. 



HYDRARGYRI SUBMURIAS. Submuriate of quick- 

 silver. Calomel. ]^e\v name, Protochlorlde of Mercury. See 

 Calomel. 



HYOSCYAMUS. See Henbane. 



INFUSIONS. — Infusa. Medicated liquids, made by pour- 

 ing boiling or cold water on any vegetable or medicine whose 

 virtues it is capable of extracting. When the medicinal prin- 

 ciples of a vegetable are of a volatile nature, and liable to eva- 

 porate by boiling, they are extracted by being steeped in hot or 

 cold water. The liquid thus obtained is termed hot or cold in- 

 fusion. Chamomile flowers, peppermint, and other aromatic 

 herbs, are to be infused in hot water ; logwood, guaiacum, and 

 bark require to be boiled, the latter a short time only, the two 

 former much longer. (See Decoction.) The menstruum of 

 infusions is water ; if alcohol be used instead, the preparation is 

 then called a tincture, and, when wine or vinegar is employed, 

 it is termed a medicated wine or vineo:ar. 



INJECTIONS. — Injection es. Liquids (generally medicated) 

 which are injected into any cavity of the body, by means of a 

 eyringe, gum-bottle, or other instrument. 



lODINIUM. Iodine. [This substance is found in a state 

 of nature in many marine plants. Its properties are stimulant, 

 and its chief action seems directed to the absorbents, which it 

 excites in a very high degree. 



Iodine is now extensively employed by scientific veterinarians. 

 It is thus described by Mr. Morton : — 



" Although iodine and its compounds have not yet come into 

 general use amongst veterinarians, I have little doubt but that 



