hridZ^ and all the Echinites^ fomt whereof arc plainly, all in fome 
nieafure flcllatedzt the cop. 
127. The Belemnites which are all ftriated from a centn^ yec 
in the whole affeft a pyramidal fo^m ; feem to have fomv/hat alfa 
of an Ant'monial^ but a more prevalent quantity of a nitrom 
fait, 
128. The Conchites^ Pe^inites^ ^nd OJiracites^ whether tranf- 
verfly firiated^ or from the commiffures to the ri;;;, feem to own 
their origin to urinous [alts^ which shoot like wife from a cmter 
(as fuppofefrom the hinges of thefe fiones^ but genetally are moft 
extended to one fide, as may be fecn in the branched figure form- 
ed on the furface of urine by freezing, in Mr. Hooks Micrography'^ ; 
who fe /rice not obtainmg much above the quadrant o( z circle ^ 
whatever other difference there may be, in this refped at leail is 
agreeable to our fiones, 
129. To which add the Ophioniorphit^s^ or Cornua ^mmonis^ 
riioft probably formed either by two falls shooting different ways, 
which by thwarting one another make a helical figure, juft as two 
oppofice winds or waters make a Turbo ; or elfe by fome fimple, 
yet unknown y2f/^, that affefts fuch a figure: perhaps the ftems 
and branchings bended in a mofl: excellent and regular order, like 
the ribs of fome of out Ophiomorphit's, obfervcdby Mr. Hook.* 
in Reguh-s Martis ^ellatm^ might not a little conduce to the clears 
ins; this matter. ' ^ 
130. Hovv^near I am to the mark in thefe former Conjeftures, I 
dare not too temerarioufly refolve : But as to the formation of 
the Rhomboidtal SeleniteSyTab. 2. Fig, with a little more con- 
fidence I iliall venture to pronounce it, to com.e from a Tartar eom 
fait in the Earth ; having obferved in the Honorable Mr. Soj/'s 
way of preparing Tartarized Spirit of Wine"", that the Calx of 
Tartar being fated with the fhleg?natick part of the Spirit^, and 
diifolved by the heat ; fet to cool, fomtimes fhoots (I dare not 
fay always) exadly into fuch Rhomboideal figures made up of 
plates^ and the whole Rhomboids fomtimes iffuing out of one an- 
other, juft as we find the Selenites often do. 
131. More might have been added concerning fome other 
formed flones hereafter to be mention'd ; but I have now only rime 
to hint my Hypothefis^ which I fuppofe may be fuiiiciently done 
•i Ihid.-m. * Microgrd^hiaohferv.i^. r Effay r. of theunfuccefsfulnefs of Expcriracnts- 
Q- 2 . ^iW 
