INTRODUCTION. 3 
back to his little workshop, and began immedi- 
ately to experimentize upon the mineral. 
It appears most probable that Cascariolo looked 
upon the sulphate of baryta, or heavy-spar,—for 
such was the object of his curiosity,—as a metallic 
ore, and supposed that by heating it with charcoal 
in a hot fire, he would be able to extract a metal 
—perhaps gold! His hopes in this respect were 
not realized, but he nevertheless succeeded in ob- 
taining one of the most curious of substances,— 
,a body which, to use the words of an old physicist, 
“absorbs the rays of the sun by day, to emit them 
by night.” 
At this period there was at Bologna a well- 
known alchemist, Scipio Begatello, who had ren- 
dered himself remarkable by his attachment to the 
art of gold-making ; and in the year 1602 the ecb- 
bler brought to him the product of his experiments, 
showed him the substance produced by calcination 
(and which he called by the mystical name of lapis 
solaris), and endeavoured to convince Begatello 
that from the weight of the stone which had fur- 
nished it, from its power of attracting and retain- 
ing the golden heht of the sun, this shining sub- 
stance would doubtless be fit for converting the 
. more ignoble metals into gold—the sol of the al- 
chemists. He showed it also to Maginus, a dis- 
tinguished professor of mathematics, who, being 
no adept, did not keep the matter a secret, as Be- 
