348 ALKALIES AND ALKALINE EARTHS 



alkaline, interfere with tlie secretions from the pancreas, liver, and 

 intestines and thereby hinder digestion. 



Circulatory System. These agents, by lessening the acidity of 

 the gastric juice, enter the circulation and increase the alkalinity of 

 the blood. The bicarbonate taken in large doses upon an empty 

 stomach enters the blood unchanged, where by decomposing the neu- 

 tral sodium phosphate present, it forms the acid phosphate, thus 

 increasing the acidity of the blood and urine. 



Uses. They are used as antacids, laxatives, antidotes to acid 

 poisons and as astringents. 



THE GROUP IN DETAIL 

 POTASSIUM 



The principal effects produced by the potassium ion are depres- 

 sion of the central nervous system and all kinds of muscle including 

 the heart. 



The entire central nervous system is affected. The reflexes are 

 first depressed, then the medulla. The heart is said to be stimulated 

 by small doses, fatigued or weakened by medium doses, and para- 

 lyzed by large ones. This is due to direct depression of the heart 

 muscle. In poisoning, the heart ceases before respirations stop ; the 

 muscles are weakened and their irritability lessened. The above 

 effects are said to be obtained only after intravenous doses according 

 to some writers, while others insist that they may be caused by large 

 doses administered subcutaneously or per os. Aiiimals daily take in 

 large amounts with their food, so that those administered as medi- 

 cine may be considered as inert. The difficulty in securing toxic 

 action from potassium salts is due to their rapid excretion. The 

 salts of potash are never used in medicine for the action of the 

 potassium ion, since its action on the heart cannot be utilized. 



POTASSII HYDROXIDUM 



Synonyms. Potassium Hydroxide, Caustic Potash, Potassium 



Hydrate 



Occurs as dry, white translucent pencils or fused masses, odorless 

 or having a feeble odor of lye, and having a very acrid and caustic 

 taste. Deliquescent in air, soluble in 0.9 part of water, 3 of alcohol, 

 and 2.5 of glycerin. 



Liquor Potassii — 5 per cent, of potassium hydroxide in water. 



Doses. Not often used internally. 



Potassii cum Calce. Potassium with lime, Vienna Paste. 

 Greyish white deliquescent powder, containing about equal parts of 

 potassium hydroxide and calcium oxide. 



