In view of the important work of R. E. Gibson on the elevation of the inversion temperature of quartz with increased pressure, and the discovery by V.B. Meen of high-quartz in certain of the Canadian hypothermal veins, are we still to accept Lindgren's estimate of the temperature ranges of deposition of the various classes of deposits commonly called hydrothermal without making necessary adjustments dependent upon the depth at which mineralization took place?