POTASSIUM CHLORATE 185 



acquiring a pink colour, is boiled, and the crystals formed in 

 cooling are purified by re-solution in boiling water. They 

 are colourless rhomboidal plates, have a cool saline taste, are 

 soluble in sixteen parts of cold water, and in two parts at 

 212 Fahr. The salt readily parts with its oxygen ; thrown 

 on red-hot coal it deflagrates ; triturated with sulphur or 

 phosphorus it explodes. Explosive gases are also evolved 

 when it is heated with sulphuric or hydrochloric acid. 



ACTIONS AND USES. Potassium chlorate is antiseptic, 

 sialagogue, and diuretic ; used externally, it is antiseptic, 

 mildly stimulant, and refrigerant. It is less soluble than 

 sodium chlorate, which it closely resembles. 



MEDICINAL USES. The chlorate was formerly thought to 

 act by liberating oxygen in the tissues and blood. That 

 this is erroneous is proved by the fact that ninety per cent, 

 of the drug can be recovered in the urine. At the same 

 time chlorates are slowly reduced with liberation of oxygen 

 in the presence of putrid decomposing organic matter. The 

 salt after absorption is excreted in the saliva, from mucous 

 surfaces, and by the kidneys, and if putrefaction is going 

 on in these situations the oxidising and antiseptic effects of 

 the drug are produced. Poisonous doses highly oxidise the 

 haemoglobin of the blood, converting it into methaemoglobin, 

 which holds oxygen firmly, and thus interferes with aeration 

 of blood in the remote capillaries. Respiration accordingly 

 is impaired, blood-pressure falls, haematuria and asphyxial 

 convulsions precede death. A small quantity mixed with 

 recently-drawn blood causes it to assume a chocolate colour 

 and to give the spectrum of methaemoglobin, and many red 

 cells are destroyed. Used as a wash or gargle, it stimulates 

 the salivary and buccal glands, moistening the dry, parched 

 mouth. It soothes and heals aphthous eruptions and ulcera- 

 tions of the mouth and throat ; while in catarrh, sore- 

 throat, and bronchitis it thins the secretions and promotes 

 expectoration. 



It is readily absorbed, and in febrile and blood-poisoning 

 cases has been believed to exert antiseptic effects, depending 

 upon its saline properties, and on its readily parting with 

 oxygen and chloric acid. But this explanation is not 

 altogether satisfactory, for, as alreadv stated, it is excreted 



