P H I L O S O P H I A E
Fiffilis 1hic lapis clt, & fic pellucct, ut unda
'Illim is , vel cryftallus dc monte refe&a ,
Sic perfert flammas, ut non pellucidus effe
Poft nequeat, licet ignefeat ; nimioque calore
2000
Vertitur in calccm , non funditur, exagitante.
Non frontem ipfe diu , fi maceret unda- , politam
Servabitpalcafquc leves, ut tuccina , friflus
Adducet, jungetque fibi , merfafquc liquore
Quodam , a re fortem quem dicimus effe , tumultu 2005
Ebullit valido, & turbas concinnat, ut ignis.
Quadratis plerumque lolet
{
qx
.
frontibus effe ,
Flexibus & folidis proin bis proltare quaternis:
Sed paulum obliqux quadratae funt tibi frontes,
Et non, qua plani, xquales funt undique flexus; 2010
Obtulos gradibus plus Icfc pandere centum,
V ix gradibus feptem decies lcrvabis acutos .
Dc folidis flexus gemini , oppofitiouc viciflim
His
l D eferibit h ic ip fam cryftal-
lum Islandicam ,
te
p ro p o n it ca , *
q u x pertinent ad ejus polituram ,
q u x om n ia excerpiu c q u x ftio n c
O p tica N e v v to n i 14 , ubi is h x c
h ab e t „ Eft cryftallus ifta lapis
,, pellucidus , &: fiffilis, aquam ,
, , vel cryftallum dc rupe pclluci-
,, ditate x au ip a ra n s ,co lo ris expers,
ca lo risa a co p a tie n s,u t r.tiam can.
„ defieri poffit,ncc ramen in pofte-
,, rum transluccre d e lin a t ,
te
calo-
,, re v eh em en tiflim o in calccm rc-
„ d igitur, n cc tam en liquescit. In
„ aqua , diem u n u m , ycl alterum
,, m acerata p olituram fuam natu-
„ ralcm a m i t t i t . Pan no a ffrifla
, , attrah it fibi ftram en ta
te
alia
,, co rp o ra levia inftar c lc d r i , vel
„ vitri ,
te
cum aqu a forti c-
„ b u llitio n cm c i e t . v id e tu r cfle
, , lapis ejus g e n e r is , quod v u lg o
„ ralcum a p p ella t:c. In ven itur ca
, , forte f p e c i c , q u x eft paralie-
,, lepipedi obliqui lateribus fex pa-
„ ra lle lo g r a m m is ,
te
o d o angulis
folidis. P ara liclo gram m o rum an-
, , gurli obtufi funt gra d u u m io r .
>,
acuti autem grad uum
„ A n g u lo r u m fo lid o rum d uo fibi
, , in vicem ex adverfo oppofiti con-
,, tin entur ternis angulis obtufis ,
, , reliqui autem fex angulis obtufis
, , lin g u lis ,
te
binis acutis . F indit
,, fe facile in plana , q u x fint
,, laterum cuivis parallela , in alia
,, autem plana non it e m . Findit
,, fe in fuperficicm p olitam ,
te
ni-
,, tentem , n on illam quidem per-
, , feci e planam , fed afperam ali-
i,
q u a n tu lu m ,
te
inaequalem
.
In-
,, terraditur facillim e ,
te
p rop ter
,, n im iam m ollitiem x g r e adm o 1
, , d um p e r p o lit u r . Politur m elius
„ fuper vitro l x v i ,
te
fpeculari,
, , q u am fuper m etallo , & a dh uc
,, melius fortaftc in pice, corio , aut
,, m em bran a . O p o rte b it autem
,, deinceps oleo , vel ovi a lb um in e
,, defricari ad rafuras im p le n d a s ,
,,
te
lx vig au d as , quo d em um p a-
,, f l o valde pellucida e v a d e t ,
te
e x p o l i t a ,, H x c quidem N c v v r o -
n u s ,
te
ex ipfo N o ft e r : addit
autem N c v v to n u s ipfc et illud ,,
„ V e r u m
ad
p lurim a quidem cx -
„ perim en ta
nihil opus eft, ut
^ poliatur,,.
