[ 12(59] 
Two E^traiis of the Journall of the Phil. &dc. of 
Oxford ; one containing a Paper\ communicate 
e^/ March 31,1685, by the Reverend J)rW?A\\Sj 
Prefident of that Soc. concerning the fir ength of 
Memory when applied with due attention : the 
other^ dated Dec. i^thji6%^ydefcribing a large 
Stone Voided by way of Vrine. 
The fir ji ExtraH^ 
UPON Occafion of a Difcourfe, at a meeting of 
the Fhilofophical Society zt Oxford[Marcb 24, i(58i) 
concerning the Advaiitage which thofe may have('as to 
Memory and the Application thereof J who want their 
Sight: Dr Wallis confirmed it by this confideration. 
That, even we, that have our Ey- light, can yet with 
more advantage apply our Memory (in matters of in- 
tent confideration^ by Night, in the Dark, when a ii 
things are Quiet; than by Day, when fights and Noifes 
are apt to divert our Thoughts. And gave inftance^ in 
his own application of his Memory, by Night, (in per- 
forming Arithmetical Operations in great numbers ) 
better then, by Day, he could have done; and, even 
by Day, we may better do it with our Eys ftiut^ than 
©pen. 
And, becaufe fome prefent feemed to be furprifed at 
the particulars mentioned j he did at their next meet- 
ing [Mar. 31. i6%s) give this further accountof it. 
Having had the Curiofity, heretofore, to try, how 
iar the ftrength of Memory would fufEce me, to per- 
fform fome Arithmetical Operations {'ais Multiplicatio7ty 
Divifioriy ExtraUionoi^ootSy 6ccJ without the aihftance 
of Pen and Ink, or ought equivalent thereunto ; And 
finding it to fticcced well (tor inftauce/in Extraidling 
