20 2 On the Animal Calculus. 
prepared a good Quantity of it, both imrec- 
tified and reftified, and made it one in a great 
Variety of briskly fermenting Mixtures, in 
hopes tliac by thus putting its Parts in a brisk 
Motion, it might have made fome ImpreflTion 
on the CalctiluSy but it had no Effed. 
6, I made a Preparation of Tartar of Vi- 
triol, by mixing one part of Oil of Vitriol, 
with twice its Quantity of hot Water, in 
which were Pieces of Calculus and Tartar; 
the Calculus emitted Bubbles, but not the 
Tartar : Then I poured in gradually 01, Tart, 
when both Calculus and Tartar emitted for 
fome Minutes a great Quantity of Bubbles. The 
Tartar was almoft at once diffolved, and the 
Calculus was very rotten and brittle, but it 
was not of the very hard kind. Sal Tartar 
which is a fixt Alkaly, being Icfs corrofive 
than Spirit of Harts-horn which is a volatile 
Alkaly. 
Experiment III. 
I. T Made a Solution of it in Water, in the 
A Proportion of an Ounce of Sal Tartar 
to four of Water; and made many brisk Fer- 
mencr^tions, with feveral Portions of this al- 
kaline 
