MicroGRAPHtas. 49 
through the Microfcope.' Some of thefe' threads 1 have obferved al to | 
be pieced‘or made up of feveral fhort Jengths.of differently coloured 
pe ( as\f'may fo callithem ) ‘asa line. appearing about two,inches!Jong 
through the! Adcrofcope 5» has been compounded: of about half ahanch of 
a Peach colour, ¢ of alovely Grafi-green, + 0f:ah inch niore.of a bright 
Scarlet,and the reft of the line of a Watchét blew. Others of themswere . 
much otherwife coloured 5) the variety being almoft infinite. . (Another 
thing which is very: obfervable, is, that ‘if you find any. place where thé 
colours. are-very broad and con{picuous to the nakedeeye;, youmay;: by ; 
prefling that place with your finger’, make thecolours change places,and — 
go from one part to another.: vib bas tig} ot sunisnos Hoy i aud 
- There is one Phenomenon more, which may, \if-care -be |tifedsexhi+ 
bit to the beholder, asithas divers times to me, an.exceeding !pleafant, 
and not lefsinftruttive Spectacle 5» And that is, if curiofity an ditigence 
be nfed 5 you may fo fplit this admirable Subftance:, that you may have 
pretty large Plates ( in comparifomof: thofe fmalléer ones which you:may 
obferve inthe Rings.) that are perhaps an 4 ora % ae of aninchover; 
each of them appearing through the A/cro/cope moft Curioutly; intirely, ‘ 
and uniformly adorned with {ome one vivid colour: this, if ¢xamined — 
with the Adicrofcope, may be plainly perceived tobe in all partsof it e- 
gually thick. _ Two, three; or more ot thefe lying oné upon anothér, ex- 
hibit oftentimes curious conipounded colours, which produce |fuch a 
Compofitum , asone would {carce imagine fhould bethe refult of fuch in- 
gredients: As perhapsa faizt yellow and a blew may produce,a very deg 
purple. But: whenanonwe.come to the more {tri examination,of Kes 
Phenomena, ind to inquire into the.caufes and reafons of. thefe producti- 
-ens,we fhall,I hope, make it more conceivable how they are produced; 
and fhew them to be no other then the natural and neceflary effects ari- 
from the peculiar union of concurrent caufes. ; 6 fy eo! 
Thefe Phenomena being {fo various, and {0 truly admirable, it will cer- 
tainly be very well worth our inquiry , to examine the caufesand reafons 
of them,and to confider, whether from thefe caufes demonftratively, evi- 
denced , may not be deduced the'true. caufes of the production of 
kind of Colours. And I therathér now do it; inftead of an Appen- 
dix or Digreffion to this Hiftory, thei upon the occafion of examining 
the Colours in Peacocks, or other Feathers, becaufe this Subjett,, .as it 
does afford more variety of particular Colours , fo does it afford: much 
bettet wayes of examining each circumftance. . And, this will be made 
_manifeft to him that confiders , firft,. that this laminated body is more 
fimple and thenthe parts of Peacocks feathers, this confifting on- 
ly of an indefinite number of plain and {mooth Plates, heaped up,, or 77-, 
cumbent on eachother: Next, that the parts of this body are much more 
manageable, tobe divided or joyned; thenthe parts of a Peacocks fea~ 
ther,or any other fubftance that I know. And thirdly, becaufe that inthis! 
we are able froma colourlef& body to produce feveral coloured bodies; 
affording all the variety of Colours imaginable : And feveral, others; 
which the fubfequent Inquiry will make sae ts aegran: :'93 a 
, ¢ 
