CHAPTER XVII. 



SUMMARY OF RESULTS. 



Purpose of this chapter. — A vGrj large poi'tioii of tlio foregoing' pages is nec- 

 essarily occupied by detailed descriptions, written in order to enable readers 

 to judge whether the facts warrant the opinions expressed, and by discus- 

 sions of a somewliat technical character. There may be those, however, 

 who will be interested to know in brief what conclusions have been reached, 

 but who have no inclination to undertake the somewhat serious task of 

 weighing the evidence adduced and of following the arguments in detail. 

 For such readers this chapter is written ; but it must be understood that 

 for full and fully qualified statements reference must be made to the body 

 of the report. 



statistics and history. — The commcrcial status of quicksilver is peculiar. It 

 seems to be three or more times as abundant in nature as silver; and since 

 1850 the weight of silver extracted is about six-tenths that of quicksilver; 

 but the total value of the latter is less than one-sixteenth that of the former 

 metal. This is due to the limited demand for mercury, which is employed in 

 laro-e quantities only for amalgamating gold and silver ores and for the man- 

 ufacture of vermilion. If it should prove practicable to extirpate phylloxera 

 with mercury, this application will greatly benefit the quicksilver miners as 

 well as the vine-growers. 



Five regions in the world are yielding or have yielded great quantities 

 of this metal. They are Ahnaden, in Spain; Idria, in Austria; Kwei-Chau, 

 in China; Huancavelica, in Peru, and the Coast Ranges of California. Of 

 the Chinese region little is known, except that it is extremely rich; in the 

 opinion of a very competent judge, the richest of all. Almaden has pro- 



