at fiTft one of them would not appear bigger than a 
pins head i yet in moving forwards it would at the lame 
time diffufe it felt circularly, and make as it were a 
great Halo, adornd with the colours of the J^atn-baw^ 
and fo very vivid, as afforded a very pleafant, and at 
firft furprizing, fpedacle ; thefe Phantafms often nimbr 
ly fucceeding one another, and lafting till they loft 
themfelves againft or under the thick Scum 4. The 
motions of this odd Liquor were not only various, but 
frequently Vortical ; to be fatisfyed of which I lome- 
times put fliort bitsofftraw, or Fragments of fome fuch 
like ftuff, upon the difcovered part of the lurface of 
the Liquor, by which they were carryed towards very 
diftant, if not oppolite, parts of the Veffelat the fame 
time. But to make the Vortical motion more evident, 
I feverall times detach d confiderably large pieces of 
the thick Scum, from the rettof the body : and had 
the pleafure to fee them move both with a progref- 
five motion in crooked lines, and with a motion about 
their own middle moft parts. All this while the Li- 
quor, whofe parts were thus briskly mov'd, was a(9:ual- 
ly cold, as to fenfe. To oWerve what the prelence, 
or abfence, of the free jlir would do to this Liquor 
I caufed many fpoonfulls of it, with fome of the Scum, 
to be put into a Cylindrical Glafs, which tho* large it 
felf, had a Neck belonging to it, that was but about 
the bignefs of ones Thumb, that it might be well ftopt 
with a Cork. But having by this means kept the free 
^ir from having a full and immediate coiitacft with 
the whole furface of the mixture, as it had when that 
mixture lay in the wide- mouth'd Veffel ; I could not 
perceive the Liquor to move to and fro, no not tho* 
the Orifice of the Neck were left open: whereas 
having at the fame time powr d fome of the Liquor 
into a very (hallow and wide Mouthed VefTel, calld in 
the Ihops a clear cak'd Glafs, it moved rather more 
than J 
