948 Extenfion of Cardan’s Rule to the 
or quantities lefs than nothing, or of the poffibility of 
fubtradling a greater quantity from a leffer), that the o- 
therwife clear and elegant fcience of algebra has been 
clouded and obfcured, and rendered difgufting to num- 
bers of men of a juft tafte for reafoning ; who are apt 
to complain of it, and defpife it, on that account. And, 
doubtlefs, they have too much reafon to do fo, and to 
lay, in the words of the famous Monfieur des cartes 
in his differtation De Methodo , page 1 1 , Algebram verb , 
ut folet doceri , animadverti certis regulis et numerandi 
for mulls it a ejfe content am , ut videafur potius ars qua dam 
confufa , cujus ufu ingenium quodammodb turbatur et ob- 
fcuratur , quam fcientia , qua excolatur et perfpicacius 
reddatur. If this complaint was juft in des cartes’s 
time, there is certainly much more reafon for it now. 
50. The paffage above alluded to in Dr. wallis’s 
algebra, is in the 48th chapter, pages 179, 180, of the 
folio edition at London in 1685. And Mr. de moi- 
vre’s method of extradling the cube-root of an im- 
pollible binomial quantity, as 81 + s/ - 2700, or a + 
\/ -b, is publifhed in the appendix to the fecond vo- 
lume of profeflor saunderson’s algebra, pages 744, 
745, 746, 747. It is very ingenious, and Ihews that 
author’s great fkill in the ufe and management of al- 
gebraick 
