Quantity of infipid water chance to rife, nor will they 
Exhale very much in an open fire, whereas we can vola- 
tili:{e fix parts of eight of our Calculous matter : and ob- 
taine Salts and oy Is. 
But to pafs on .-The chymijls^who of all men fuppofe their 
6>^^Wowj- the leaft fubjed: to uncertainty, being grounded 
on experiments pihey deicribe the Concretions of the body, 
and particularly this morbid one by calling thcmTarta- 
reous : who conclude they have fufficiently accounted for 
the nature of a body, if they can but ca 11 it Tartar , which 
muft be acknowledged to conii&.oi Acid ^ and fixt Salts^ 
called Alcalz^at, andoffome Tarra damnata ^ tho* it be 
Very little in proportion to the other Salts, 
If we compare fuch of the Calculus which 
have often made, with the aforetaid Tar tar, we may then 
infer what Uttle reafon there is toEclipfe its nature by that 
denomination. We Diftilled an ounce of Calculus Huma- 
^22^/, that was recently cutt out of a body, which aflForded 
about two drams of a brown Spirit ^ nearer to that of 
HartS'hornthanVrine. We put the Caput mortuum upon 
the f///^/ and reduced it to near a dram, thereft burning 
and fmoaking away. 
Another time we diftilled in a naked fire a Stone that 
weighed two ounces, the yapor came over upon a good 
ftrefs of fire, and letled in the form of S<»/^ without any 
liquor^ of which we preferved only a dram^ it appeared 
very hrown and tafted hitter^ as the fetid oil of Harts-horn 
and other Empyreumattcal Oils doe. We examined by 
boy ling and evaporating water from the Caput mortuum^ 
whether it held any fixt Salt, but found none. The Caput 
mortuum weighed one ounce and fix drams, fo that it loft 
only two drams in the DtjHllation that is only two 
drams came over xheHelme. We proceeded farther and 
placed this Caput mortuum upon a Tejt in an open fire, 
where 
