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EFFECTS OF MEDICINE ON HORSES. 
By Mr. Wm. Percivall. 
BARYTES. 
BARYTA, or barytes, was introduced into this country in the 
latter part of the last century by Dr. Withering, who found it 
abounding in the lead-mines of the northern parts of England; 
and from him the mineral in its native state obtained the appella- 
tion of Witherite, it having been, before that time, known to the 
chemists of the continent by the name of terra ponderosa, or 
heavy spar. It occurs naturally both in the state of carbonate 
and sulphate : in the former, however, in this country, more ge- 
nerally than in the latter. 
Witherite, or the native carbonate of barytes, is used in medi- 
cine principally for the purpose of obtaining two barytic salts of 
comparatively high medicinal powers to any possessed by the car- 
bonate itself, — the nitrate and the chloride of barytes , the latter 
only being admitted into the London Pharmacopeia. The former, 
however, besides being potently medicinal, is very useful as af- 
fording the readiest means of procuring pure barytes , a form in 
which it is virulently caustic, and, like unslacked lime, absorbs 
water with avidity, becoming then comparatively harmless. From 
the apparent success of some of my experiments on the efficacy of 
barytes as an antidote for farcy and glanders, I was induced to 
take the pains of preparing the mineral in its pure or caustic form 
for myself, and found the process by no means either a difficult 
or a tedious one. Sir H. Davy, by the force of his galvanic 
power, extracted from the pure barytes a metallic base, which he 
named barium; proving that what we regarded as “pure” was 
nothing beyond a metallic oxyde, or compound of oxygen and 
barium. 
Carbonate of Barium. 
Case I. — A brown mare has been in the infirmary for some 
weeks on account of an attack of farcy in the near hind leg, for 
which she has been treated in the ordinary way, having been lat- 
terly taking the farcy ball*. In spite of all that has been done, 
however, the disease has been of late making advances; and now, 
some tumefaction of the submaxillary gland, also, of the near side, 
has taken place, accompanied by a slight discharge from the cor- 
* A composition of sulphate of copper, antimony, and common turpentine. 
