(47'^)^ 
Experiment the Fcurtfr. 
In one of that fore of Conical Glaflfes that has been already more 
than once defcrib'd, we had put uponfome Filings of Copper a 
convenient quantity of our Spirit of Suit y and though we obferv'd, 
tbac for a great while it would not part with its deep and fomevvhat 
muddy tinfture 3 yet we left it in the window for many weeks 
longer5and at length,towards the latter end of December ^^n^ found 
it to have loft its tinaure, fo much that the liquor appear'd like 
commoD water. Upon whichobfervation, though the time of the 
year were unpromifing, I thought fit to try , whether the Air in 
that feafon would not have fome, though perhaps but a flow, ope- 
ration on the Saline Spirit, and accordingly taking out the Giafs- 
ftopple to give free accefs to the outward Air, we obferv'd, that 
in Tome hours its operation on the liquor Was fcarce fenfible , but 
within about 24 hours the Menfirmm had acquired not juft its for- 
mer colour, but a foiuewhat faint and moderately tranfparent 
green : So that this tinned Menfiruum^^z it had been very flow in 
lofing its colour, foit did but flowly and imperfcflly re acquire 
IHnvt not In the foregoing Experiments mnAe mention of any Vha* 
nomenaof them relating to the Spnng of the included Air, l^- 
uufe 1 do not remember^that they were [uch as invited me to drarv any 
pofitive Conclujion from them, andmy fiience on ihu occajion mij be 
the more allowable ^becauje the vqaj of further making fuch Objervati" 
ms may be fufficiently deduc'd from the infuing Tryals ; in reciting of 
which I alter very little, andin fomeofthemnoPatall^ theexfreffi^ 
ens 1 find them regijlerd in^ though more than once the Phaenomena 
that relate to the Air's Elajlic power be mingled in the fame Experi- 
ment with the mention of its operations uponColours. 
'Ihe Spring of the Air and its variations^ by the wajes novo known 
to many of the Curious^ beingthings that manifeflly apfear to have a 
notable inter eft in divers Phenomena of Nature^ whofe Caufes j if not 
t hemfelves alfi, were unknown to former Fhilofophers ; it feem'd an 
Attempt i though not very promijing , yet worth the makings to try 
whether the Spring of theAir^ which may divers way es^ as by He at^ 
Corner efjion^ C^c. be increased, may not by fome other way than Cold 
and Dilatation be weaken d: And having often found ^lenflruums 
that, corrde Metals,fo as to produce bubbles to invigorate the (irengtb 
0. 
