141 J . 
This Stone lent us for thirteen Dramms, iBiiil: either have 
been Averdupoife^ of elfe is wafted fomething, for I found it 
only to weigh 
In the jlir 12 dr. —36^. 
In Water 6 dr. ■';2A^&^' 
The difference betwixt the weight pf ] 
this Stone fb called, in the Jir and in I 5 dr. 48 gr. 
Water comes to j 
The proportion betwixt this Concrete and Water, proves 
to be as 7 56 to J48j0r as two and fbmcwhatmore than a fixth 
to one. This extraodinary Pondm or Gravity makes tlie 
matter of a greater confideration, and worthy our further 
Inquiry whether there be not ibme Metallick Ingre- 
dient in it. 
Whilft I was making thefe Tryals, I was willing to com- 
pare this matter with common C^^//&, which I found fpeci- 
fically lighter, bearing only the proportion to Water of $2 1 
to 290, confiderably iliort of that of 2 to one. Shells and 
Teftaceous Bodies do very near agree with this matter; 
which takes off the former opinion that this Patient, had 
perhaps devoured Wall^ Lime, and fuch Uke Teftaceous 
Matter, from whence the Stone might receive its original : 
For thisbeing broken into peices, will, not fb eafily cement a» 
gain into fb compaft a Body as it was formerly of, as we fee 
in Whiteing that is lighter than Chalk: Wherefore this being 
vaftly heavyer than Chdky can fcarfe be thought a Concretion 
of fuch a matter. 
I then compared it with petrified Water, being an Icecle 
that was broken off' a Grc?r^t?, where the petrifying Spring did 
furnifti enough : This came very near the Gravity of our 
Rarity, and the ufiaal weight of ordinary Stones ; a peice 
that weighed five drams out of the Water, difcovered its 
weight to bearethe proportion of 403 to i84,or 75.6 to 345 
to that of Water. This Anomalous Subftance being fb 
near the weight of our petrifyed Water, would almoft in- 
T cline 
