4 ’ 
265° “. Fourcroy’s Examination of 
der was nothing but the matter of the calculus altered and» 
changed im. its nature.”—Citizen Fourcroy concludes his; 
abridgement of Dr. Pearfon’s paper as follows: ‘ I thought 
it my duty to give an account of all his (Dr. Pearfon’s] 
experiments and refults, in order that it might be more eafy . 
to compare what he has done with the refearches of Scheele 
and thofe made by myfelf. By giving a fimilan abridgement } 
of the latter alfo, it may be then feen whether Dr. Pearfon 
has made ufeful additions to the difcoveries which preceded 
his labour, and whether the. conclufions which he thinks 
himfelf authorifed to deduce from his experiments can be 
found in them.’? Cit. Fourcroy then proceeds as follows :} 
At fhart Account’ of the Refearches of Scheele and Bergman, 
and of thofe made by my/felf. 
Whey the illuftrious Scheele read in 1776, to the Academy 
of Stockholm, his examination of the bezoar, or ftone of the 
human bladder, no one then had an accurate idea of the 
mature of this concretion, though Margraf had already ob- 
ferved, that it was not formed of an abforbing earth, as was 
pretty generally believed before him, and as has been re- 
peated fo often fince in many works on medicine. Scheele 
obferves in the beginning of his differtation, that he exa- 
mined feveral calculi, {meoth, rough, or angular; that he 
found them poflefs the fame nature and properties: it is 
flherefore the hiftory of the genus that he meant. to give. 
His memoir is divided into ten fections. To afcertain pro; 
perly the value of his labour, I muft here make the reader 
follow him through thefe fections. : 
{. The fulphurie acid diluted produces no. effet on the : 
calculus ; but concentrated by. diftillation it diffolves it: the 
folution difilled to drynefs leaves a black coal, giving off 
fulphureous acid fumes. 
tI. The muriatic acid, diluted er concentrated, has no 
effect ever by ebulliztion on the urinary calculus. 
tI, Weak 
