BAILEY. | Mineral Waters. — 51 
characteristics. Acids in the stomach assist the action of the 
pepsin in digestion; they also increase the flow of the gastric 
juice. Acids are very useful in that variety of dyspepsia in 
which not enough acid is secreted. 
‘‘All acids convert proteids into acid-albumins, which are in- 
soluble in moderately strong, but soluble in concentrated or 
very weak acids. Upon this precipitation of proteids depends 
their astringent action. 
‘‘Alkalies will reduce the acidity of the chyme, and thus in- 
crease the alkilinity of the intestinal fluids, even if they are 
themselves neutralized and absorbed before reaching the duo- 
denum. In this way they may favor the emulsification of fats, 
and the action of the pancreatic ferments, if there is not sufficient 
alkali in the intestine.’’ In a normal condition of the sys- 
tem, this action would be of no value, but where there is an ex- 
cess of mucus, or too great acidity, the alkalies are very useful. 
On account of the action of the undissociated salt, the secretion 
of the urine is increased. 
The free acids that are found in waters are sulfuric and oc- 
casionally hydrochloric. The sulfuric acid is derived from the 
oxidation of pyrite (FeS,). The Rio Vinagre, in South Amer- 
ica, is supplied by such acid springs, and it is estimated that it 
carries daily to the ocean an amount of acid equal to 82,720 
pounds of oil of vitriol and 69,638 pounds of concentrated mu- 
riatic acid. There are some noted springs of this character, as, 
for instance, the Oak Orchard acid water, in New York, the 
Texas salt springs, and the Thermal acid springs of California. 
The Abilene, Kan., artesian well contains a notable quantity of 
free hydrochloric acid. 
Waters of this class usually contain an abundance of such 
elements as iron and aluminum, so that their therapeutic prop- 
erties may be considered as being due to these elements. ‘‘ Be- 
ing very astringent, the stronger acid waters are useful in relaxed 
states of the mucous membranes, especially when characterized 
by diarrhea and dysentery. ‘They have also been used with 
great effect in hemoptysis, colliquative sweats, and in depraved 
