it fomewhat of a Sky-colour, he was , upon owning his furprife 
thereat , informed , that a dozen of them being put in , they 
would dye it to almoft a full Azure, Which is touch't here, 
that 5 the Experiment being fo eafie to make, it may betried, 
when the feafori furnifhes thofe Infeds 5 meantime, it feemsnot 
more incredible , that this Creature fhould yield a Sky-colour, 
when put in water , than that Gochineel , which alfo is but an 
Infed , fliould afford a fine red, when fteep'd in the fame Liquor. 
An Account 
iiriLooob' Of Some Books. 
-T^2 >£fe Tome troifieme et dernier des Lettrcs .de Jii. DES^ 
^ - ARTMS. 'snv ■' r'. / . 
As the two firft Tomes oi M,i>es-Cartes\i\s> Letters , contain 
Queftions , for the moft part of a Moral and Phyftdogical Nature, 
propofedjto y ^d anfwer^d by him- fo this coniifts of the Gon- 
tefts, he had upon fe vera! Subjects with divers Mea eliiinent in: his 
time./ • - . . 
To pafs by that fliarp Conteft, he was engaged in by fojne 
Profeffors of Divinity at Utrecht , who endeavoured to difcredit 
his Philofophy , as leading to Libertinifnie and Atheifme , -not- 
withftandinghemade it fomEchhis bufinefs , as to aflert the Ex- 
igence of a Deity , snd the Immortality of a Soul: We fliall 
take notice of what is more to our purpofe , vid, the Differences, 
he had touching his Dioftricks and Geometry, 
As for \i\%:T>iopricks y thought great part of the Learned 
World have much efteem'd - that Tteatife ., as leaving little to be 
faid after him upon that Subjed 5 yet there have not been wanting 
Mathematicians, wlio have declared their difagreement from his 
Principles in that Dodrine, The firfl of them was the Jefuit 'Bour- 
^i/;?,Mathematick ProfefTorinthe Colledgof C/er^^?;?^ atP/^m^but 
this difference was foon at an end. A fecond was Mr. Bobbs^ upon 
whofe account he wrote feveral Lnms w Merfemus ^ containing 
many remarks conducing to the Knowledge of the Nature of Re- 
fleciion mdRefraBion. Butthe Perfon, that did mofl learnediy 
and refolucely attack the faid Dioftricks , was Monfieuri^^'ra^^j 
writing 
