158' The Philippine Journal of Science mv 



Radium content of Philippine waters. — Samples of twenty 

 typical waters, from which the emanation had been removed, 

 were acidified, sealed up in proper containers, and allowed to 

 stand at least one month. They were then tested for radium 

 content, by the method previously outlined. In no case was there 

 any indication of radioactivity. 



In addition, 15 liters of Batangas water (No. 1), 15 liters 

 of Los Banos water (No. 12), and 5 liters of Sibul Springs water 

 (Nos. 4 and 5) were evaporated to small bulk and similarly 

 tested. The first two showed no emanation, and the third 

 showed a trace. 



The radioactivity of the waters studied was, therefore, 

 primarily due to emanation derived from the materials in the 

 ground with which the water had been in contact and not to 

 dissolved radium salts. 



DISCUSSION 



The work has not proceeded sufficiently to justify many con- 

 clusions. The typical Philippine water supplies studied possess 

 no abnormal features so far as their radioactivity is concerned. 

 Though some of them are moderately high in radium-emanation 

 content, none show an excessive amount, compared with waters 

 from other countries reported in the literature. 10 



Since hot water is a poorer solvent of gases than cold water, 

 it is to be expected that the radioactivity of hot springs should, 

 in general, be low. With the exception of the Los Banos water 

 (No. 12), most of the thermal waters studied in the course of 

 this work showed little or no activity. 11 



In general, the average activity of igneous rocks is greater 

 than that of the sedimentary, 12 and it is to be expected that water 

 from the former material should show higher emanation content. 

 Thus Sahlbom 13 found that the water from sedimentary deposits 

 was much lower in activity than that from primary rocks; 

 further, that wells bored in the acid rocks showed the highest 

 activity. In the Philippines the relatively small number of de- 



10 Cf. Schlundt, H., Bull. U. S. Geol. Surv. (1909), No. 395, 31; Jown. 

 Phys. Chem. (1914), 18, 662. Isitani, D., Proc. Tokyo Math. Physic. Soc. 

 (1912), and following years. 



11 The average temperature of ground waters in the lowlands of Luzon 

 is about 28° C. 



12 Cf. Clarke, F. W., Data of geochemistry, Bull. U. S. Geol. Surv. (1916), 

 No. 616, 122. 



"Sahlbom, N., Arkiv Kemi, Min. Geol. (1915), 6, No. 3, 1-52; through 

 Chem. Abst. (1916), 10, 1134. 



