hades of
colour, from a light green to a dark olive, with a degree of
transparency equal to that of wax and susceptible of a fine polish. By
some writers it is called a black stone; but this colour may have been
given to it by frequent handling when in use, and by the grime of age
since. It was called by the Romans, from the use made of it in
fabricating measures of weight, _lapis aequipondus_, and from its
supposed efficacy in the cure of diseases of the kidneys _lapis
nephriticus_. Fabreti says that it got the name of _lapis Lydius_ from
the locality from which it was believed to have come. It is a kind of
nephrite or jade, a mineral which usually occurs in talcose or
magnesian rocks. At one time it was supposed to exist only on the
river Kara-Kash, in the Kuen Luen mountains north of Cashmere, and for
thousands of years the mines of that locality were the only known
worked ones of pure jade. It has since, however, been found in New
Zealand and in India; while the discoverers of South America obtained
specimens of it in its natural state from the natives of Peru, who
used it for making axes and arrow-heads, and gave it the name of
_piedra de yjada_, from which comes our common word _jade_, on account
of its use as a supposed cure for the iliac passion. It may be
mentioned that there is a mineral closely allied to jade called
"Saussurite," discovered by the great geologist whose name it bears
near Monte Rosa, and since found on the borders of the Lake of Geneva,
near Genoa, and in Corsica. It is possible that the martyr-stones may
be made of this mineral, for they have not been analysed. But if they
are, as it is supposed, made of true jade, the fact opens up many
important questions.

No stone has a more remarkable history. It is an object of interest
alike to the geologist and the antiquarian; and in spite of the most
patient inquiry its antecedents are surrounded with a mystery which
cannot be satisfactorily solved. Its antiquity is beyond doubt. In the
most ancient books of China it is noticed as one of the articles of
tribute paid to the emperor. Dr. Schliemann found it among the ruins
of Troy. But its history stretches into the misty past far anterior in
time to all ordinary records, to Cyclopean constructions, or to
pictured and sculptured stones. One of the most curious things brought
to light in connection with the prehistoric annals of our race is the
wide diffusion of this mineral in regions as far apart as