334- ANNUAL REGISTER, 1758.
infallible, having feen forac bones of the mineral kind that were con- cave, as if they had formerly con- tained marro*v.
Thus has this controverfy been canvafled pro and con ; but as I have had the opportunity of exa- mining great qjantities of this foiTile, particularly in my father's cabinet, who had various pieces of it, I have found moll of that dug about the Hartz to be of a mineral kind.
This being taken for granted, we are nex: to confider the matter it is compoled of. Some tiiini: with ^ibavius. Part 3, Singular. 1. iS. c. 17. that it is a bituminous earth ; and others fay it is a kind of agate petriiled : bat to me it feems moft probable that it is made of a clay, or fatttlh earth, called in Jjatin Morga, or Marl, which is very plentiful in this country, and ferves to manure the ground, in- ftead of dung. According to the figure this earth lies in under- ground, when the petrifying water comes to it, and caufes it to grow hard, fo it remains, and tlius be- comes fometimes a well-fhapen bone, and often a lump of matter of no diflincl form at all. This formation is not perfccled at once : for it is obferved, that fome pieces lying in a place where there is room for incrcafe, will grow to a mcn- ilrous lize.
This fofiile hath feveral names, viz. XJnicorriu minerale, Ebur fojjile , Ojieitcs, Monoceros 'vulgi. Lit ho- marga alba, &c. The moft com- mon term it is known by, is Unicor- nu foJJiU ; bat I can fee no rpafoo why it Ihould ra'hcr be called Uni- corn than any ocher animal, lincf it is found of all forts of forms, and thofe pieces refembling the horn of 'an unicorn bat very firely lobe met
V'ith
It is moft commonly of a light grey, black, or yellowifti colour, and very feldom perfedly white : fometimes it is as hard as a ftone, and other times foft like clay, and grows harder the longer it is ex- pofed to the air. It has commonly neither fmell or tafte, yet fome- times I have found it with a fcent like that of quinces ; which pro- bably might proceed from a bitu- minous fubftance mixed with the petrifying water. It is introduced in the Materia Medic a, and the whiteft and melloweft is reckoned the beft for that purpofe. The common people try it by putting it into cold water; and that which caufes moft bubbles to rife, they count for the beft fort. The rea- fon of the rifing of thefe bubbles is, becaufe as this fofiile is full of pores, wherein air is contained, the water getting into them, drives out the air, which being fpecifi- cally lighter than the water rifes in the form of thofe bubbles to the furface.
%he common people looked for- merly upon it as a medicine of ex- traordinary efficacy, thinking it to be the true unicorn; but fince it is come to be common, it hath loft much of its repute. It ope- rates very like the Terra figillata, abforbs, aftringe?, and pro.notes perfpiration, (Vide Francifc. Joel. Pract. tom. 5.) and is one of the ingredients of the Bezoardic pow- der defcribed by D. Ludovici in Pharmacopeia vioderno faculo appli- canda, and produces a very good efteft, unlefs a fymptomatic coftive- nefs forbids its ufe. Externally it ferves in puftulary eruptions and erofions about the pudendum and fundament in children, and in eye- waters, Laftly, D. Hoffman, ia his Clwvis Schraderiar.a, admo-
oilhes
