298 The Philippine Journal of Science im 



The table is self-explanatory, for the most part, but there are 

 a few points in connection with it that merit attention. 



The springs in the list are typical and are representative of 

 the country in which the work was done. They comprise the 

 prominent and better known sources along the route of travel, 

 among them several used for salt manufacture (Salinas, Mainit) 

 and several hot mineral springs with reputations for medicinal 

 virtues (Itogon, Mainit, Comilias). 



The highest activity recorded (1,325 X 1(H 2 ) was found in 

 Adukpung spring, in Kiangan. 



It will be noted that Piko spring, in Kiangan, was examined 

 both in 1916 and 1917 and that there is a marked discrepancy 

 between the two determinations. This difference does not neces- 

 sarily indicate a variation in emanation content, nor even a 

 serious error in the determinations, as the water from the spring 

 in question flows into a small, covered reservoir before it is 

 allowed to emerge ; therefore a sample cannot be secured directly 

 at the point of emergence. 



As might be expected in a volcanic region, there are a number 

 of solfataras in the area under discussion, notably at Bolotoc, 

 at Daklan, and near Monhuyhuy. The one at Daklan, which 

 we visited this year, is characterized by a number of vents, from 

 which hot gases and vapors emerge, principally hydrogen sul- 

 phide, sulphur dioxide, and steam. We were unable to find 

 any springs at this place. There were a number of excavations 

 in which surface run-off and perhaps condensed steam had col- 

 lected, forming great caldrons of hot water, some of them used 

 as baths through which the gases and vapors bubbled. There 

 were also a number of hot mud "springs," where the gases broke 

 through semiliquid mud with the peculiar sound from which the 

 solfatara presumably has derived its Igorot names (Barutbarut, 

 Badukbuk). As the waters in the excavations just mentioned 

 were probably surface run-off, and as they were constantly 

 aerated by the gases bubbling through them, their activity was 



6 This spring is peculiar. It is located in the wall of a rice paddy and 

 emerges at a level only a few decimeters below that of the water in the field. 

 As it is separated from the rice-paddy water by less than 5 decimeters of 

 earth, this spring looks like a mere seepage. We were assured, however, 

 that it is a true spring, whose flow does not fail throughout the year, even 

 during the months when the rice field is quite dry. Analysis of the water 

 in the rice paddy showed marked differences from that from the spring, and 

 the determination of activity seems to furnish further proof that the source 

 is a real spring. 



