382 The Philippine Journal of Science 1914 



teeth among users of hard water; also, that the nursing period 

 of mothers lasts longer. 



The term "mineral water" is somewhat confusing. Practically 

 all natural waters contain dissolved mineral matter, and might 

 properly be classified as "mineral waters," However, in the 

 more restricted meaning of the term, only those waters are 

 included which have peculiar characteristics distinguishing them 

 from ordinary spring or well water. According to L. Griin- 

 hut,=^ a mineral water is differentiated by (a) a high content 

 of soluble matter, (&) a high content of rare or unusual sub- 

 stances, or (c) a high temperature. The following are the sub- 

 stances on the basis of which he makes his classification and the 

 limiting values for each substance : 



Substance. Parts per million. 



Total solids 1,000 



Free carbondioxide 250 



Lithium ion (Li') 1 



Strontium ion (Sr") 10 



Barium ion (Ba°*) 5 



Ferrous or ferric ion (Fe°° resp. Fe*"*) 10 



Bromine ion (Br') 5 



Iodine ion (!') 1 



Fluorine ion (F') 2 



Hydroarsenate ion (HAsO"<) 1.3 



Metaarsenious acid (HAs 0;) 1 



Total sulphur 1 



Metaboric acid (HBO2) 5 



Alkalinity 4 (equivalent to 0.34 gram of NaHCOs per liter). 



Radium emanation 3.5 Mache units per liter. 



Temperature 20° C." 



" Obviously this value could not be used ip a countrj' 'ike the Philippines, where in many 

 localities the avei-age temperature is much higher and water is usually from 25° to 30° C. 



If any of these values ■''' is exceeded, the corresponding water 

 may be regarded as a mineral water. The curative properties 

 sometimes attributed to various mineral springs appear grossly 

 exaggerated, and it hardly seems plausible that the small 

 amounts of mineral salts contained in such waters should have 

 the wonderful power ascribed to them. No doubt the pleasant 

 surroundings of the average medicinal spring resort, combined 

 with fresh air, good food, and general relaxation and exercise, 

 contribute their share toward the improvement in the health 



" Zeitschr. Ba.hieol. (1912), 4, 433-6; Wasser u. Abivasser (1912), 5, 

 417-20; Pkarm. Zentralh. (1914), 55, 180. 



" This classification has been adopted by the Verein der Kurorte und 

 Mineralquellen-Interessenten Deutschlands, Oesterreich-Ungarns und der 

 Schweiz. 



