15*2 INORGANIC AGENTS 



cardiac mascle, and, finally, by stoppage of the heart in 

 systole. 



Barium chloride also directly excites the muscular walls 

 of the capillaries and, like physostigmine, increases vascular 

 tension in small doses. 



Micscles. — Barium chloride stimulates muscular contrac- 

 tion when it is applied locally. The potassium salts 

 antagonize the action of barium chloride on the circulation 

 and muscles. 



Summary. — Circulatory stimulant, and purgative in 

 large doses. 



Uses. — Barium chloride is a new remedy in veterinary 

 medicine. "We cannot, therefore, speak of it with absolute 

 certainty yet. The doses required to produce catharsis in 

 the horse are almost toxic. The quantity should be propor- 

 tioned to the weight of the patient, and well diluted with 

 water. The average dose for the horse, intertracheally, is 

 1 gm., or 15 gr., in one -half ounce of water. The drug has 

 been employed with reputed success to cause rapid purging 

 in colic and obstinate constipation of horses. 



The action is usually reliable and safe, but some deaths 

 have been attributed to the action of barium chloride. 



Magnesium. 

 (The meted is not used in medicine,) 



Magnesii Sulphas. Magnesium Sulphate. MgSO^ + 7 HjO. 

 (U. S. & B. P.) 



Synonym. — Epsom salt, sal amarum, sal Epsomense, sal 

 anglicum, sulfas magnesicus, etc., E.; magnesia sulfurica, 

 P. G.; sulfate de magnesie, sel d'Epsom, sel de sedlitz, sel 

 amer, Fr.; bittersalz, schwefelsaure magnesia, G. 



Derivation. — It is obtained from native dolomite, a 

 double carbonate of magnesium and calcium, or magnesite 

 (MgC03). MgC03 + H,SO, = MgSO, + H,0 + CO, 



Properties. — Small, colorless, rhombic prisms, or acicular 

 crystals, without odor, and having a cooling, saline and 



