come to bccloggM in their motion • Whence it fccmM reafonable to expefl 
that upon the fleunion of the Saline panicles into fuch a Body , as they h?.d 
conftituced beforCjihe redintegrated Sal Armoniack having, neerupon , the 
fame Texture, would, upon its being rediffolvM, produce the fame, or a noc 
mnch inferior degree of Coldnefs ; And hereupon , though \ well enough 
forefaw that an Armoniack folution, being boy I'd up in Earthen vefTels (for 
Glass ones are too chargeable) would, by piercing them , both lofe fome of 
the more fukle parts, and [hereby fomewhat impaire the texture of the reft ♦ 
yet I was not decelvM in £xpefting,that the dry Salt, remaining in the pip- 
kins,being rediifolv'd in a due proportion of water,wouId very confiderably 
infrigidateit^as may further appear by theNores^which for your greater fatif- 
fadion you will find here fubjoynM-as (oon as I have told you, that, though ' 
for want of other vefTelsI was firft reduc'd to raakeufe of £arthenones,and 
the rather, becaufe fome Metaliin VefTels will be injnrM by the diffolvM 
Sal Armoniackjif it beboylM in them yet I afterwards found fome conveni- 
encies in VefTels of other Mettall,as of iron ^ whereof you may command a 
further Account. 
March the 2yth,the Thermofcope in the Air was at 8f inches being piif 
into a fomewhat large evaporating glafs, fiird with water , it fell ( after it - 
ftaid a pretty while^ and had been agitated in the liquor) to 8 . inches : thef! 
about half the Salt,or left,t:hat had been ukd twice beforehand felt much Itfs 
cold than the water, being put in and ftirr*d about,the tindcd Spirit fublided 
with a vifible progrefs, rill it was fain manifeftly beneath 4. inches • and then, 
having caufed fome water to be frtfhiy pump*d and brought in ^ thougl^ the 
newly mentioned Solution were mixt with it, yet it prefently made the Spirit 
of Wine manifeftly to alcend in thelnftrument, much fafter^ than one would ^ 
baveeipeded^c^^r. 
And thus much may fuffice for ttk time concerning our F rigor i fit k^E^p^" 
riment which I fcarce doubt but the Ciirtepf.ns will lay hold on as very fa- 
vourable to fome of their Tenents which you will eafily believe , it is not 
to the Opinion, 1 have elfewhere oppos'd , of thofe Modern Philofophers^ 
that would hvjQ Sdt-fetre to be the Frimum VrlgiL m:( though I found by 
trial, that, whilft 'tis aftually diffolving, it gives a much coniiderabler degree 
of Cold, than ocherwife«) But about the Reflexions, thac may be made on 
this Experiment,and the Variationsj and Improvements.^ llfes of it, though 
1 have divers things lying by me yet,fince you have feen fsveral of them al- 
ready, and may command a fight of the reft , 1 fhall foi biar the mention of 
them here^not thinking it proper, to fwell the bulk of this Letter with ihttv, 
jin Account of two Buoks lately printed in Londoji, 
l.EVC LIDIS E LB M E NTA G E O M ET RI C A.novo 
ordlne ac mtthGdo demonfrrata. In this compe«dlous and pretty Edition, the 
Anonymous Author pretends to have reiidi ed tliefe Elenients more exptdi- 
tious by bringing all together into one place; what belongs 1:0 one and the 
fame fab jed ; Comprifing i ,whai: jB^ :/;'./ Iiach fald of f /W, f/rtighc, In- 
terfering one another, and Parallel, l¥hat he htith dcmonllrated of a 
Single Triangle^ and oiT-k^^^Ja C^mti^^ rd one m:h another* ? .What of 
• the Circle , and its Trcf-o \]:^. 4 ■ , pyopoftims inTriang't'. t-.i-.d 
ocher Figure?, ..5,Whac.of ^^^^Jr as ...... ■..,,^>?^7i/jgLiadc of Lines di.\c;[jy 
