296 AGRICULTURAL ANALYSIS 



has made investigations of the deposits of niter in Southern Cali- 

 fornia, and has collected practically all of the exact information 

 that is available on the subject. 60 Nearly all of the niter deposits 

 which have been discovered up to the present time are found in 

 the northern part of San Bernardino County, and the beds are 

 found particularly along the shore lines, or old beaches that 

 mark the boundary of Death Valley as it doubtless appeared 

 ouring the eocene times. The beds and clays contain the de- 

 posits which have been worn by erosive agencies into knobs, 

 buttes and ridges that have been compared by some to haystacks 

 and potato hills. 



Until lately the principal value of the niter hills was sup- 

 posed to lie solely in the surface coating. When this is removed, 

 deposits which are full of other saline compounds are exposed. 

 This top coating is, in accordance with the custom followed in 

 Chile, called by the Spanish name "caliche." This caliche ranges 

 in depth from a few inches to several feet. The surface caliche 

 evidently owes its deposits of salt to the upward capillary flow 

 of water from below, induced by the rapid evaporation at the 

 surface in a region comparatively devoid of rains. The niter 

 deposit is in the form of a soluble salt, which readily permeates 

 the clay and separates into a white crystalline deposit. In Chile 

 the colors of the caliche are usually yellow, pink and green, but 

 in California a creamy yellow is the characteristic color; though 

 pinks and greens are sometimes found. The quantity of niter 

 contained in the caliche is extremely minute as compared with 

 the more concentrated deposits of Chile, and hence it is evident 

 that these extensive deposits in California will not become avail- 

 able commercially, until the more concentrated deposits in Chile 

 and other similar localities are exhausted. The chief difficulty in 

 the California deposits is that the niter is associated with other 

 soluble salts, chiefly common salt, from which it is with some 

 difficulty separated. The following table gives typical examples 

 of the composition of the soluble salts of the caliche, not the 

 representative or mean composition, but the extreme types of 

 samples containing various proportions of niter : 



60 California State Mining Bureau, Bulletin 24, 1902 : 154. 



