THE ALKALINE AND BORACIC LAKES OF CALIFORNIA. 179 



Moore, of San Francisco, yielded 18.86 per cent, 

 of crystallized borax. In addition to this the de- 

 posit at the bottom of the other portions of the 

 basin, although less productive, still contains a 

 large amount of borax. 



Water collected from* Borax Lake, in Septem- 

 ber, 1833, was found by Mr. Moore to contain 

 2401.56 grains of solid matter to the gallon, of 

 which about one-half was common salt, one-quar- 

 ter carbonate of sodium, and the remainder 

 chiefly anhydrous borax, equal to 535.08 grains 

 of crystallized salt to the gallon. Traces of 

 iodine and bromine were also detected. A sam- 

 ple of water taken from the interior of a coffer- 

 dam sunk in the middle of the lake, and which 

 had been allowed to fill by percolation from the 

 bottom upward, was found to be more concen- 

 trated, yielding 3573.46 grains of solid matter to 

 the gallon, but it contained the same ingredients, 

 and in nearly the same proportions as the water 

 from the lake itself. When evaporated to dry- 

 ness, this water yields a considerable quantity of 

 finely-divided carbon, resulting from the various 

 organic bodies which have been dissolved in it. 



Mud from the bottom of Borax Lake is in 

 high repute among the local Indians as an insecti- 

 cide, and is used in the following way : The head 

 of the patient is thickly plastered with mud, 

 which is well rubbed in, and then allowed to be- 

 come perfectly dry ; when dry, it is removed by 

 rubbing between the hands, and with it disap- 

 pears the colony of parasites. Ordinary clay is, 

 under pressure of circumstances, sometimes em- 

 ployed for this process of shampooing, but when 

 alkaline or boracic mud is available, it is consid- 

 ered more efficacious. 



When this locality was visited by me in 1866, 

 borax was manufactured exclusively from the 

 native crystals of crude salt, while the mud in 

 which they were found was returned to the lake 

 after a mechanical separation of the crystals by 

 washing. The extraction of boracic mud was 

 affected by the aid of sheet-iron coffer-dams. The 

 only apparatus employed consisted of a raft, cov- 

 ered by a shingled roof, provided with an aper- 

 ture in its centre about fifteen feet square, above 

 which were hung, by suitable tackle, four coffer- 

 dams, each six feet square in horizontal section, 

 and nine feet in depth. This raft, or barge, was 

 successively moored in parallel lines across the 

 surface of the lake, and at each station the four 

 dams were sunk simultaneously by their own 

 weight into the mud forming the bottom. 



When they had thus become well imbedded, 

 the water was baled out, and the mud and crys- 



tals removed, by means of buckets, into rectan- 

 gular washing -vats, into which a continuous 

 stream of water was introduced from the lake 

 by Chinese pumps, the contents being at the 

 same time constantly agitated by the aid of 

 wooden rakes. In this way the muddy water 

 continually flowed off, finally leaving a certain 

 amount of crude borax at the bottom of each 

 tank ; this was purified by recrystallization. 

 From the density acquired by the 70,000 gallons 

 of water daily employed for this purpose, it is 

 evident that only about one half of the borax ex- 

 isting in the form of crystals was thus obtained, 

 while the mud was again returned to the lake. 



Instead of the coffer-dams, a small hand- 

 dredging machine, worked, like the former, by 

 Chinese labor, was subsequently introduced ; but 

 the mud brought up by it was subjected to the 

 wasteful process of washing before described. 



The crystals of crude borax thus daily ob- 

 tained amounted to about 3,000 pounds ; these 

 were dissolved in boiling water, and recrystallized 

 in large lead-lined vessels, from which the puri- 

 fied salt was removed to be packed into boxes, 

 each containing 114 pounds, in which it was for- 

 warded to San Francisco. The loss of weight 

 experienced in the process of purification amount- 

 ed to about thirteen per cent. 



Shortly after my visit in 1866, the manufact- 

 ure of refined boras at Big Borax Lake was 

 suspended, and I am not aware whether it has 

 now been resumed, but the works do not appear 

 to have been in operation in 1874. 



Little Borax Lake covers an area of about 

 thirty acres, and is usually dry during the months 

 of September and October ; it is then covered 

 by a white crust, which is collected by Chinese 

 laborers and carried to the works, where it is re- 

 fined by recrystallization. Ulexite, a double borate 

 of sodium and calcium, is brought to this place 

 from Wadsworth, in the State of Nevada — a 

 great distance, with several transshipments — to 

 be treated at these works ; it appears that on ac- 

 count of the presence of carbonate of sodium, 

 and the cheapness of fuel, this can be done more 

 cheaply here than in Nevada. 



Clear Lake is a larpe and picturesque sheet 

 of water, twenty-five miles long, by, about seven 

 wide, surrounded by mountains, which in many 

 places rise abruptly from the water's edge. Boat- 

 life on this lake is delightful ; the water is smooth, 

 there is usually a sufficient breeze for sailing, 

 and should it fall calm, an Indian can always be 

 hired to row. 



Lying about a mile beyond the ridge which 



