Mircriooraprat dv 15 
todrinefs and moifture, {6 that withone breathing uponvit, Thave made 
it untwilt'a whole bout, and the Index or Hand has thew’d or pointed to 
various diviftons on'the upper Face or Ring of the’ Inftrument, according 
as it was carried neerer'and ‘neerer to'the fire; or ‘as'the heat of the Sun 
increafed uponit.§ » uly  Sbaal doidw soltnaimaxs od¥ coe 
Other trials have made with Gutfirings, bur firid them nothing neer | 
fo fenfible; though they alfo maybe fo contriv’d:as toexhibit:the 
changes of the Air; as to/drinefs and moifturesboth by theirftretching 
and {brinking ‘in lengthy ‘and: alfo by-their wreathing: and:unwreathing — 
themfelvesy but-thefe are’ nothing neer {0 exact or: {o-tender,foritheir va- 
rying property will ina Jittle time change very muchy But there are fe | 
veral other Vegetable fubftances that‘aré much mére fenfible then even 
this Beard-of'a wilde Ost; fuch Thave found:thé Beard of the fécd:of | 
Mutk-grafs; or Geranium mofthatum, and thofé of other kinds df Craness 
bil eeds;.and the like.: But always the {maller the wreathing: fubftance 
be, the more fenfible is it of the mutations of the! Air, a conjecture at 
the reafon of which I fhall by and by add.) Y over rend bee 
_ The lower'end of this wreath’d Cylinder being ftuck upright ina little 
foft Wax;) fothat the bended part or index of it lay horizontal, Thave , 
obferv'd it always with moifture rounwreath it felf from the Eaft (For 
inftance)by the South to the Weft,and fo by the North tothe Eaft again, 
moving with the Sun (as we commonly fay) and with sr poe 
tore-twilt, and wreath it felf she contrary way, namely, fron He Ke 
(for inftance> by. the North'to the Weltand Pomnbdae 4 x “¥ brie 
The caufe of all which Phexomena, feems to be the differing texture 
of the parts of thefe bodies, each of them (efpecially the Beard of a wilde 
Ost, and of Mosk-grafs feed.) feeming to have tio kind of fab{tanees,one 
that is very porous. loofejand {pongie,into which the watry {teams of the 
Air may be very eafily forced, which will be thereby, {well'd and'extend- 
ed in its, dimenfions, juft as, we may obfetve all kind of Vegetable fub- 
ftance upon fteeping in water to {well and grow bigger and longer. Anda | 
fecond that is more hard and clofe,into;which the water can very little,or 
hot at all penetrate, this therefore retaining always very neer the fame 
dimenfions; and the other. ftretching and fhrinking, according as there 
is more or lefs moifture or water in its pores, by reafon of the make and 
thape of the parts, the!whole body mutt neceflarily unwreath and 
_.»Andupon this Principle, it is vety eafie to make feveral forts of con 
‘bya aces that fhould chu wreath ail unwreath themfelves, either by | 
_ heatand cold, or by drinefs, and moifture, or by any greater or lef force, 
from whatever caufe it: proceed, whether from gravity or weight, O08 
wind which is motion of the Air, or from fome {pringing body, 
Or the like, .. eS ee ——r ' HM 
5S. 
__~ Thishad Itime, [{hould enlarge rhuch more upon 5 for it feemstome 
| to be the very firft footltep of Senfation, and Animate motion, the moft 
Plain,fimple,and obvious contrivance that Nature has made ule of to ae | 
duce a motion, next ‘to that of Rarefadtion and Condenfation by ind 
