356 THE POPULAR SCIENCE MONTHLY. 



account for the commencement of crystallization, which, so far as we 

 can judge, must have been in an exceedingly weak solution. Nor does 

 it perhaps seem possible that such complete seclusion from ascending 

 and descending currents could in any way be secured. The winter 

 rains pour in quite fierce torrents of drainage- water from all sides, 

 often rendering the entire lake decidedly turbid, and of course causing 

 more or less of commotion in every part. And in addition to this 

 is the diffusion of particles, caused by the changes of temperature 

 throughout the year. 



In whatever light, therefore, the question is viewed, it is not free 

 from difficulties. And yet at the same time it is but right to recall 

 the fact that these green crystals are in their nature tincal, though 

 such tincal as has never been found elsewhere, and that the crystals 

 of tincal are perhaps in other localities formed subject to the same 

 conditions as here prevail. 



We turn now to Hachinhama, the other locality mentioned, as af- 

 fording the borax-supply of California. This is on the southern side 

 of Clear Lake, about four miles west of Borax Lake, which it closely 

 resembles in its features, though much smaller, being an oval lagoon 

 about four hundred yards in length. "We have, as there, a sheet of 

 clear alkaline- water, with a bottom of soft, plastic mud. This mud 

 has been bored to about the same depth as in the explorations at Borax 

 Lake, without its lower limit being reached. 



The evidences that the alkaline pool occupies the space of an ex- 

 tinct crater, are more manifest here than at Borax Lake, as the in- 

 closing walls still remain, though abraded on their northern extremity, 

 while on the south they rise abruptly to the great mountain-summit of 

 Conoktai. 



The water of Hachinhama holds in solution the salts of soda in the 

 following proportions : Sodium carbonate, *754 ; sodium chloride, 

 083 ; sodium biborate, '163. The mud throughout its entire depth 

 is richly stored with the same salts, but without any development 

 whatever of crystallization of any kind. 



After the cessation of work at Borax Lake, in 1868, attention was 

 turned to the resources of Hachinhama. Of course, the style of work- 

 ing must be totally different, for here was no borax ready formed, no 

 green crystals needing simply solution and recrystallization. All that 

 was available was a sheet of water, holding the salts above recorded. 

 The problem, then, was to separate in purity the borax the only 

 one of sufficient value to be worth the effort and leave the others. 



Borax being the least soluble of the three salts, and at the same 

 time much more soluble in hot water than in cold, it was argued that, 

 were the water of Hachinhama sufficiently concentrated by boiling 

 and then allowed to cool slowly, the borax would crystallize out, leav- 

 ing the carbonate and chloride in solution. 



This is correct in theory, and in laboratory practice the results 



