Ox the Compofition and’Properties, Se. 39 
diftilied urine by alcohol, was led to depart from his adored 
mafter’s opinion, with refpect to the nature of calculi; 
although he acknowledges the merit of Paracelfus, in having 
difcovered the folvent Ludus, (a calcareous ftone alfo called 
Septarium,) which Van Helmont fays is preferable to alka- 
line lixivium. He alfo fays, that when the archeus fpirit of 
urine meets with a volatile earthy fpirit, and does not aét in 
a due manner, a concretion will be formed; but, in a 
healthy ftate, although all urine contains the matter of 
urinary calculi, no concretion can take place, becaufe the 
archeus, er vital power of the bladder, counteracts its 
formation. : 
' As to the kind ef earth compofing calculi, the only dif- 
tinétion of earths, till about the laft half century, was into 
abforbent and non-abforbent; but, fince the abforbent 
earths were diftinguifhed into calcareous, magnefia, and 
alumine or clay, the calcareous was confidered to be the 
earth of urinary concretions; apparently however for no 
other reafon but its obvious properties, and its extenfive 
diffufion through the whole animal kingdom. 
At length, viz. in 1776, the experiments of the wonder- 
ful Scheele were publifhed in Sweden, but were fcarcely 
known in this country till 1785. Thefe experiments ex- 
ploded the opinion of the earthy nature of calculi, and fub- 
ftituted that of their confifting of a peculiar acid, refembling 
the fuccinic, and of a gelatinous matter, without any earth. 
Afterwards about ,*. of their weight of lime was found by 
Bergman; which, for a caufe now well known, had cluded 
the acutenefs of Scheele. Although the experiments of 
Scheele were confeffedly unqueftionable, and were ably fup- 
ported by the learned Bergman, fome very eminent chemifts, - 
having obtained different refults by their’ own experiments, 
adopted a dificrent opinion of the compofition of thefe con- 
cretions. The immortal, and ever to be deplored, Lavoifier 
' fuppofed thefe fubftances to confift of acidulous phofphate of 
lime and animal matter, many of. them being partially 
D4 fulible ; 
