490 ANALYSIS OF THE 



does not pre-exist in the water, dissolved hy an excess of car- 

 bonic acid, but that it is produced during the evaporation, and 

 must therefore be formed by the action of carbonate of soda on 

 muriate of magnesia. 



This view of the composition of this water, accords much 

 better than the other, both with its sensible qualities, and its 

 medicinal powers. It§ taste, after the carbonic acid has esca- 

 ped from it, on exposure to the air, is rather strongly alkaline, 

 which would scarcely be the case, if it contained only four grains 

 ■of crystallised carbonate of soda in a pint, but which is to be 

 expected if it contain eighteen grains. It operates as an antacid 

 and diuretic, and is productive of much benefit in all dyspep- 

 tic affections, in diseases of the urinary organs, and in those 

 general affections of the system which require a mild tonic 

 power. Tliere are few mineral waters, Dr Saunders observes, 

 which have acquired a lygher reputation ; and there are few, 

 he adds, tliat deserve grater consideration, from the real me- 

 dicinal virtues it possesses. It will be difficult to give a satis- 

 factory account of the origin of these virtues, if we regard it as 

 water impregnated with carbonic acid, holding in solution so 

 minute a portion of carbanate of soda, with the larger propor- 

 tions of muriate of soda and carbonates of magnesia and lime. 

 But if we consider it as containing along with its free carbo- 

 nic acid, a considerable quantity of carbonate of soda, with 

 smaller proportions of muriate of soda, muriate of magnesia, 

 and muriate of lime, we assign to it a composition of much 

 greater power, and adequate to account for the effects it produ- 

 ces. Such is the activity of this water, that its medium dose is 

 only half an English pint, a degree of power which accords 

 much better with the one view of its composition than with the 



other *. 



Large 



• TLe water of Malvern may be regarded as of similar composition, only 



much 



