28 HOT SPRINGS, ARKANSAS. 



urine and perspiration and waters containing it are used in the treat- 

 ment of scrofulous diseases and eczema. 



Ferrous chloride. — The occurrence of this substance in mineral waters 

 is rather rare. When present, however, it acts as a tonic and in gen- 

 eral has the same properties as ferrous bicarbonate, already mentioned. 



Ammonium chloride. — When used internally it has the stimulating 

 effect of ammonia. It is used in nervous cases as ovaralgia, sciatica, 

 and other neuralgic disorders. In congestion of the liver its use has 

 been beneficial. Externally it is used as a wash for ulcers and sores. 

 It, however, seldom occurs in springs in quantities .large enough to be 

 of any value. 



Sulphates are frequently found in mineral waters, and when present 

 in large quantities give rise to that large class, the sulphated salines. 



Sodium and magnesium sulphates, or Glauber and Epsom salts 

 respectively, in small doses act as a laxative, in large doses as a 

 cathartic. They are both valuable in increasing the flow of the intes- 

 tinal fluids and in increasing the flow of urine, accompanied by an 

 increased elimination of urea. Waters containing these salts are of 

 great service in eliminating syphilitic, scrofulous, and malarial poisons 

 from the system, and in eliminating mercury and other metallic 

 poisons. Persons suffering from obesity, derangement of the liver, 

 and Bright' s disease are perhaps the most benefited by this class of 

 waters. It must be borne in mind that such waters should be used 

 with great care \>y the feeble and anaemic. 



Potassium, sulphate is frequently present in mineral waters, but in 

 smaller quantities than the magnesium and sodium salts. Its action 

 is practically the same as that of the other two sulphates mentioned 

 above. 



Calcium sulphate occurs in a great many mineral waters, and is the 

 component that gives to them the property of permanent hardness. It 

 is not used medicinally. 



Iron and aluminum sulphates are usually found associated with each 

 other in mineral waters. They are both powerful astringents. The 

 waters containing iron sulphate are also used as tonics, but this is not 

 nearly as good a form in which to give the iron as is the bicarbonate. 

 Because of their astringent action, waters containing these two sub- 

 stances have been used with success in treating locally inflamed parts 

 of the mucous membranes and ulcers en the outside of the body. 



Iodides. — The iodides are usually reported in mineral waters as the 

 potassium or sodium salt. They occur in nearly all cases only as traces, 

 yet their action is shown in a marked degree. They are alterative in 

 effect and are consequent!}' used in the treatment of scrofula, rheuma- 

 tism, and syphilis. While drinking waters containing iodides the flow 

 of urine is very much increased and mercurial and other metallic poi- 

 sions are rapidly eliminated from the system. 



Bromides act as alteratives in much the same way as iodides but to 

 not so marked an extent. They also act as sedatives. 



Phosphates in mineral waters are usualty reported in one of three 

 forms, viz, sodium, iron, or calcium phosphate. The sodium phos- 

 phate acts as a mild laxative, the iron phosphate as a tonic, and the 

 calcium phosphate as a medicine in those conditions of the body where 

 lime salts are deficient, as rickets, etc. 



Borates. — Boric acid is not a very common constituent of natural 

 waters, but is found as the sodium salt in springs of southern Cali- 



