768 BAB 
when pure ; but requires near twice as much when com¬ 
bined with fixed air, though an excefs of this acid renders 
it more foluble. Its attraction to the vitriolic acid is 
ftronger than that of any other fuMance, infoinuch that it 
affords the beft teft of the prefence of that acid in waters 
or elfewhere. With the nitrous and marine faits it affords 
cryftallizable faits. The marine folution is commonly tiled 
as the teft liquor for difcovering vitriolic acid. Ponderous 
earth affords a deliquefcent fait with acetous acid. It 
takes the vitriolic acid from its combination with lime ; 
and lime, on the other hand, takes the faccharine acid 
from its combinations. This earth forms an hepatic com¬ 
bination, when treated with fulphur. No other earth is 
precipitated by the Pruffian alkalis; whence it has been 
I'ufpedted to poffefs a metallic nature, though no one has 
yet fucceeded in reducing it to that form. It is not fufi- 
ble alone by the ftrongeft heat. The famous Bolognian 
phol’phorus confiffs of the vitriolated ponderous earth ig¬ 
nited for a time with home combuftible fubftance. For 
this purpofe the fpar is pulverized, then kneaded up with 
mucilage of gum tragacanth, and formed into pieces as 
thin as the blade of a knife. Thefe pieces are afterwards 
dried and firongly coloured by placing them in the midft 
of the coals of a furnace. The pieces are cleared of the 
allies by blowing' on them with bellows. In this (late if 
they be expofed'to the light for a few 1'econds, and after¬ 
wards carried into a dark place, they fhine like glowing 
coals; they even ihine under water. In procefs of time 
they lofe this property, but it may be reflored by a fecona 
heating. We are indebted to the celebrated chemifts 
Gabn r Scheele, and Bergman, for our knowledge of this 
earth ; and, for the method of obtaining it in a faitable 
degree of purity, lee the article Chemistry; 
In medicine, the muriated barytes is confidered as an eva- 
cuant, deobftruent, and tonic ; on exhibition, it has been 
found in fmall dofes to encreafe the flow of urine, promote 
perfpiration, open the bowels, and improve the appetite 
and genera! health. It has been confidered as highly ufe- 
ful in fprophulous cafes, cutaneous foulneffes, and ulcerated 
legs. In fome cancers, and confumptive affections, w'hen 
not too far advanced, it promifes to be of advantage. Its 
dofe is from fix drops to ten or twenty ; but if ever it oc- 
cafions vertigo, naufea, fevere purging, or pains in the 
bowels, it mu (I be reduced, or omitted. A courfeof this 
fliould be begun by fmall dofes, twice a day, and gradu¬ 
ally encreafed fo long as they create no inconvenience. See 
Med. Com. vol. iv. and vi. dec*2. Medical Communic. 
London, - vol. ii. 
B ARYTO'NUM,/. [from grave, and wos, ac¬ 
cent.] In the Greek grammar, denotes a verb, which ha¬ 
ving no accent marked on the laft fyllable, a grave accent 
is to be underflood. In Italian mufic, barytono anfwers to 
our common pitch of bafs, 
B ARZE/TO,. a town of Italy, in the duchy of Parma, 
feventeen miles fouth-fouth-weft of Parma. 
BARZIL'LAI, [of Heb. of bns iron; hard as 
iron.] A nobleman of the Jews. 
BAR'ZOI), a town .of Hungary, and capital of a coun¬ 
ty to which it gives name, fituated on the Hernach, be¬ 
tween Caflovia and Agria. 
BAS, a fmall ifkmd ip the Englifti Channel, near the 
coaft of France, with a fort to defend the road: there are 
not above fifty inhabitants. Lab 48. 46. N. Ion. 13.40. 
E. Ferro. 
Bas Chf.vai.iers, low or inferior knights by tenure of 
bafe military fee, as diftinguilhed from bannerets, the 
phief or fuperior knights: hence we call our Ample knights, 
viz. knights bachelors, bas chevaliers. Rennet's Glojf. to Pa- 
rock. Anliq. 
Bas en Bassei., a town of France, in the department 
of the Upper Loire, and chief place of a canton, in the 
diftridt of Moniftrol, one league north-weft of Moniftro), 
and fix and a half north of le Pay. 
Bas-relief. See Basso-relievo. 
BASAL'TES,/! [from bafal, Lat, iron, or j 3 «cr»?n£«, 
BAS 
diligentur examino.'] An heavy hard ftone, chiefly black or 
green, confiding of prlimatic cryftals, the number of whofe 
fides is uncertain. The Englilh miners call it cockle-, the 
German Jch’cerC. Its fpecific gravity is to that of water as 
3000 or upwards to xooo. It frequently contains iron 3 
and confifts either of particles of an indeterminate figure, 
or of a fparry, ftriated, or fibrous, texture. It has a flinty 
hardnefs, is infolubie by acids, and is fufible by fire. It 
is a volcanic proftuft, the three Ipecies of which are ba- 
faltes, lava, and terra pozzolana. 
The moft remarkable property of this fubftance is its 
figure, being never found in ftrata like other marbles, but 
always Handing up in the form of regular angular columns, 
compofed of a number of joints, one placed upon, and 
nicely fitted to, another, as if formed by the hands of a 
fkilful workman. From the natural hiftory of this ftone, 
it is well afeertained to have flowed in a liquid ftate, in 
prodigious ftreams, during the eruptions of burning moun¬ 
tains, and afterwards cracked in cooling, and perhaps by 
the evaporation of fome volatile fubftance, in the fame 
manner as clays, ftarch, and other fubftances, are obferved 
to crack. 
Bafaltes was originally found in columns in Ethiopia, 
2nd fragments of it in the river Tmolus, and fome other 
places. We now have it frequently, both in columns and 
fmall pieces, in Spain, Rufija, Poland, near Drefden, and 
in Silefia; but the nobleft ftore in the world feems to be 
that called the Giant’s Caufeway in Ireland, and Staffa, 
one of the Weftern Iftesof Scotland, (feeGiANT’s Cause¬ 
way and Staffa.) Great quantities of bafaltes are like- 
wile found in the neighbourhood of mount iEtna in Sici¬ 
ly, of Hecla in Iceland, and of the volcano in the illand 
of Bourbon. Thefe are the only three active volcanoes 
in whofe neighbourhood it is known to be met with; but 
it is alfo found in thcextinguilhed volcanoes in Italy, tho’ 
not in the neighbourhood of Vefuvius. In Ireland the 
bafaltes rifes far up the country, runs into the fea, croffes 
at the bottom, and rifes again on the oppofite land. In 
Staffa the whole end of the illand is fupported by natural 
ranges of pillars, moftly above fifty feet high, Handing in 
natural colonnades, according as the bays and points of 
land have formed themfelves, upon a-firm bafis of folid 
unformed rock. Above thefe, the ftratum, which reach¬ 
es to the foil or furface of the illand, varies in thicknefs, 
as the illand itfelf is formed into hills or valleys, each 
hill, which hangs over the valleys below, forming an am¬ 
ple pediment. Some of thefe, above fixty feet in thick¬ 
nefs from the bafe to the point, are formed by the Hoping 
of the hill on eacli fide, almoft into the Ih.ape of thofe ufed 
in architecture. The pillars of the Giant’s Caufeway 
Hand on the level of the beach ; from whence they may 
be traced through all degrees of elevation to the fummit 
of the higheft grounds in the neighbourhood. In moft 
places they fraud perpendicular to the horizon; but in 
fome of the capes, and particularly near Ulhet harbour, in 
the ifle of Baghery, they lie in an oblique pofition. At 
Doon point in the fame illand, and along the Balintoy 
Ihore, they form variety of regular curves. The ftone is 
black, clofe, and uniform; the varieties of colour are 
blue, reddilh, and grey ; and of all kinds of grain, from 
extreme finenefs to the coarfe granulated appearance of a 
ftone which refembles imperfeft granite, abounding in 
cryftals of fchorl chiefly black, though fometimes of. va¬ 
rious colours. Though the ftone be in general compact 
and homogeneous; yet it is remarkable, that the upper 
joint of each pillar, where it can be afeertained with any 
certainty, is always rudely formed and cellular. The grofs 
pillars alio in the capes and mountains frequently abound 
in thefe air-holes through all their parts, which fometimes 
contain fine clay, and other apparently-foreign bodies-? 
and, the irregular bafaltes beginning where the pillars 
ceafe, or lying over them, is in general extremely honey¬ 
combed ; containing in its cells cryftals of zeolite, little 
morfels of fine brown clay, fometimes very pure fteatite^ 
and in a few inftances bits of agate. Sir Jofeph Banks ob. 
ferveSj 
