On the Animal Calculus, 201 
k was the fame when the Heat and Ferment 
was renewed by throwing in fome Filings of 
Iron. 
1, The like Proportions of Oil Vit. and 
Water, with feveral kinds of powdered vitrio^ 
lie Scones or PyriteSy made violent Ferments, 
but had no Effed: on this very hard Calculus. 
3. It was the (ame with Oil of Vitriol and 
other acid Spirits, when poured on feveral al- 
kaline Bodies, fuch as powdered BelemniteSy AJ- 
teriay Coral and Oyfter-lhell, 
4. But Oil of Vitriol mixed with unredified 
Spirit of C. C. cho* it would not diflblve the 
abovementioned very hard Piece of Calculus^ 
yet with ten or twelve frefli Mixtures, it rot- 
ted and diffolved feveral pretty thick Lamina 
or Cloves of ocher Calculi ; which tho' not 
of fo compad a Texture as the other, yet were 
fo hard that I could not make any Impreflion 
on them with my Nail : But this was too pun- 
gent a Mixture to give any Hopes that the 
Bladder can bear any Degree of it, 
5. Spirit of Rye-bread being found by Chy-» 
mills a DilTolvent fo powerful as to dilTpIvc 
feveral kinds of Stones and hard Subllances, 
and yet withal fo mild, that it may with great 
Safety be held in the Hollow of the Hand 5 I 
prepared 
