36 PRODUCE OF THE WORKS PAJARO VALLEY. 



be avoided, and the occupation of furnace-men, unhealthy at the best, might be rendered less 

 destructive to health. The practice at New Almaden is that which is adopted in the mines at 

 Idria, (Carniola,) which does not yield more than an average of eight per cent, of metal ; at 

 Almaden, (Spain,) a roasting is all that is performed, which volatilize the mercury and separates 

 the sulphur as sulphurous acid. In the Palatinate and at the Duchy of Deuxponts the ore is 

 mixed with caustic lime, and distilled in iron vessels. This is the proper treatment for rich 

 cinnabar ores, which, if subjected to heat alone, suffer much loss from the escape of undecomposed 

 sulphuret carried off by the flues, and also from some sulphuret remaining undecomposed in 

 the ore. The refuse of these works contains undecomposed cinnabar, and in some specimens of 

 waste as much as ten per cent, has been found ; this is equivalent to a loss of nine per cent, 

 metal, as the pure ore yields 86 per cent, of metallic mercury. 



Notwithstanding this double loss from faulty distillation, the yield of metallic mercury is, 

 annually, very great. The total shipments of quicksilver from San Francisco, for the year 1853, 

 was 18,800 flasks, (each flask "75 lbs. weight,) or 1,410,000 lbs., valued at |683,189. In 1854 

 the number of flasks was 19,320, or 1,449,000 lbs., valued at $724,500. In the first quarter 

 of the year 1855 the export was 6,056 flasks, in the second quarter of the year 1855 the export 

 was 5,082 flasks, making for the first half of 1856 a total of 11,158 flasks, of 75 lbs. each. 

 The export was mostly to Valparaiso, Callao, San Bias, and Hong Kong. Besides this a quantity 

 was set apart for the home market, for amalgamating the gold. It would appear that the mine 

 is worked merely to supply the demand, without producing as much as the works could profitably 

 do and then seek for wider markets. The actual produce of the works is from 30 to 35,000 lbs. 

 of mercury weekly, or perhaps a maximum of 1,700,000 lbs. per annum, which, with the above 

 export, would leave 250,000 lbs. for the home market. 



According to the foregoing calculation of loss in the refuse of the furnace, it would appear 

 that the enormous quantity of 155,000 lbs. of mercury was wasted in the year 1854. 



PAJARO VALLEY. 



The Pajaro valley is a small alluvial plain which opens upon the coast of Santa Cruz county, 

 and runs at nearly a right angle to the Santa Clara valley, between which and the Salinas river 

 it is situate. Through the valley the Pajaro creek runs in its westward course from the moun- 

 tains to the ocean. The valley is of a triangular shape, broad at the shore and running nine or 

 ten miles inland, where it is cut 'short by the Llomas Muertas, or foot hills of Gavilan, which 

 separates it from the Salinas valley. On the north it is separated from the valley Santa Clara 

 by the Santa Cruz mountains. The lower portion of the valley is swamp land from the influx 

 and infiltration of sea water, forming lagoons near the bay. The land beside and above the 

 immediate river bed is of great fertility ; the bottom of alluvial sands and clays derived from 

 the soft Quaternary sandstones which form the low hills bounding the valley. These appear 

 almost horizontal, but have a small dip to the west, which is better observed at a distance. 

 These strata have undergone no disturbance (by contact) since their deposition, having been 

 elevated slowly a few feet in one unbroken mass, and belongs to the more recent elevations of 

 the tertiary period in California. The basal rock is a felspathic granite, the debris of which is 

 intermingled with and enriches the sandstone detritus. The junction of the recent sand rock 

 with the granite was not observed. In places the river cuts through heavy clays between 

 thirty and forty feet deep, near the Kanche de Los Anges. 



The upper portion only of the valley was crossed on the road to San Juan. The Santa Cruz 



