X, A, 6 



Cox and Dar Juan: Salt Industry and Resources 381 



a quantity of salt has accumulated on the surface. On the fourth 

 or the fifth day the loose earth, together with the salt, is scraped 

 into heaps and collected into leaching vats, called hornohan (from 

 the Spanish "horno," which literally means "oven), where it is 

 leached with sea water or weak brine until most of the salt has 

 been extracted and a concentration of about 10 per cent of salt 

 by weight is obtained. In many plants using the Filipino method 

 the leaching vats are located at a point intermediate between the 

 canals, where sea water is available. In this case the sea water 

 is conveyed to the vats by means of an inclined bamboo pipe, 

 the lower end of which rests upon an open-work bamboo basket, 

 or other device, to prevent violent impact of the water, and the 

 upper and larger end of which carries an earthenware jar 

 (pilon) or galvanized-iron funnel to receive the water. 



Table I. — Mechanical analyses of soil used for evaporating salt water. 



[Numbers give percentages.] 



Classification. 



Sample from- 



Las 

 Pinas. 



Bacoor. 



Aplaya, 



Batan- 



gas. 



Detritus, 2 to 1mm 



Fine earth, water-free basis: 



Coarse sand, 1 to 0.5 mm 



Medium sand, 0. 6 to 0. 26 mm .. 



Fine sand, 0. 25 to 0. 10 mm 



Very fine sand, 0. 10 to 0. 05 mm 



Silt, 0. 05 to 0. 01 mm 



Fine silt, 0.01 to 0.002 mm 



Clay (and salt) <0.002mm 



5.1 



1.8 

 5.2 

 9.5 

 16.7 

 19.8 

 29.6 

 17.4 



26.3 



11.1 

 17.4 

 12.6 

 10.6 



3.4 

 35.8 



9.1 



15.6 



7.0 

 22.9 

 30.4 

 12.2 



7.6 

 12.0 



8.0 



In the Philippines there are many salt-water shrubs and trees 

 which when green have a specific gravity greater than that of 

 water. In Rizal, Cavite, and Bulacan Provinces it is a common 

 practice among Filipinos to pluck twigs of the plant known by 

 the name of culase (Lumnitzera racemosa Willd.), which grows 

 in the marshes near salt farms and along the levees of the 

 evaporation reservoirs, strip them of their leaves, and throw 

 them in the brine to test its strength. If they sink, the brine is 

 not yet strong enough, but when they float, the brine is suffi- 

 ciently concentrated to be transferred to the crystallizing ponds, 

 called banigan. The specific gravity of the culase twigs of 

 the size used has been determined by one of us to be about 1.085, 

 or equivalent to 11.5 per cent by weight of salt. The culase 

 varies from 1.070 to 1.096, depending on whether it is smaller 



136791 — 3 



