36 THE BUREAU OF SCIENCE 



indicate what may be expected of the deposits in the different 

 parts of the Archipelago. 



At times the Bureau has been called upon to determine the 

 utility of certain substances as fertilizers, their method of ap- 

 plication, and to adjust conflicts of analyses between buyer and 

 seller. 



58. Salt. — The Bureau of Science has taken up the study of 

 the salt industry and resources of the Philippine Islands. Salt is 

 produced by the use of solar heat or, in limited quantities, by 

 the use of direct artificial heat. The methods employed for the 

 preparation of salt from sea water by the use of solar heat are 

 very crude, and the method now most commonly employed is 

 probably the original one used in these Islands. In recent years 

 the Chinese have introduced a somewhat improved method. 



The people of Mountain Province produce a small amount 

 of a poor grade of salt by evaporating water from carbonated 

 springs. At Mainit, Bontoc ; Tukukan, Ahin, and Bungabungna, 

 Ifugao; and Salinas, Nueva Vizcaya, the supplies of brine vary 

 in quantity and strength. The resources of these springs should 

 be developed in order adequately to supply Mountain Province 

 with salt at a reasonable price. 



In round numbers 20,000,000 kilograms of crude salt are pro- 

 duced annually. Scientific study of this industry will indicate 

 how to increase the output of each individual employed and to 

 improve the quality of the product. 



59. Sunlight. — The study of sunlight and its effect upon chem- 

 icals and animals has been carried on for a period of over five 

 years. The work so far has shown that the injury attributed 

 to the actinic rays of the sun is greatly exaggerated, and that 

 if these so-called actinic rays are injurious in the tropics they 

 are equally so on clear days in the other portions of the world. 

 Some effects of sunlight upon individuals whose skins do not 

 furnish the proper protection due to lack of pigmentation have 

 shown that certain reactions seriously affecting the health of 

 the individual may occur. Comparisons of sunlight intensities 

 determined at our suggestion by means of a chemical photometer 

 at various places, including Manila, Baguio, Kuala Lumpur, 

 Honolulu, Khartoum, Washington, Munich, and several places 

 in Australia have been made. These show that on clear days 

 at many of the places investigated the rate of reaction is prac- 

 tically the same; therefore, the normal sunlight intensities 

 throughout the various regions of the earth are practically 

 identical. 



It has been found that sunlight produces effects on a large 



