BOR 
salt, according to Bergman, is Composed 
of 
Acid 39 
Soda 17 
Water 44 
100 
Though borax has been in common use 
for nearly three centuries, it was only in 
1702 that Homberg, by distilling a mixture 
of borax and green vitriol, discovered the 
boracic acid. He called it narcotic or se- 
dative salt, from a notion of his that it pos- 
sessed the properties indicated by these 
names. Geoffroy afterwards discovered, 
that borax contained soda; and, at last, 
Baron proved, by a number of experiments, 
that borax is composed of boracic acid and 
soda; that it may be reproduced by com- 
bining these two substances ; and that there- 
fore the boracic acid is not formed during 
the decomposition of borax, as former che- 
mists had imagined, but is a peculiar sub- 
stance which pre-existed in that salt. This 
acid for purposes of experiment, is obtained 
from the purified borax of commerce, by 
one of the following processes: 1. To a so- 
lution of borax, in boiling water, add half 
its weight of sulphuric acid, previously di- 
luted with an equal quantity of water. Eva- 
porate the solution a little ; and, on cooling, 
shining, scaiey crystals will appear, which 
consist of boracic acid. Let them be well 
washed with distilled water, and dried on 
filtering paper. 2. Let any quantity of bo- 
rax be put into a retort, with half its weight 
of sulphuric acid, and half its weight of wa- 
ter. Boracic acid may be obtained by dis- 
tillation, and may be purified by washing 
in water, &c. as before. Boracic acid has 
the following qualities : 1. It has a solid 
form, is destitute of smell, and nearly so of 
taste : 2. It fuses, when heated, and loses 
its water of crystallization. If the heat be 
increased suddenly, before it has lost its 
water of crystallization, it sublimes ; but, 
otherwise, it melts into a glass, which is 
permanent in the strongest fire : 3. It is so- 
luble in twelve parts of cold water, and in 
three or four of boiling water : 4. This so- 
lution reddens vegetable blue colours, and 
effervesces with alkaline carbonates ; 5. It 
is soluble in alcohol, and the solution burns 
with a beautiful green flame : 6. It com- 
bines with alkalies and earths ; but the only 
important combination which it forms is 
with soda. 
BORBONIA, in botany, so called from 
Gaston Bourbon j a genus of the DiadeL 
BOR 
phia Decandria class and order. Natural 
order of Papilionaceae or Leguminosae. Es- 
sential character; calyx acuminate, spiny; 
stigma emarginate; legume mucronate. 
There are six species. B. ericifolia, is a 
small subvillose shrub, with small ovate li- 
near leaves, nerveless, smooth above, vil- 
lose beneath, revolute ; heads sessile, with 
small flowers. These plants grow naturally 
at the Cape of Good Hope, where they rise 
to the height of ten or twelve feet ; but they 
are seldom more than four or five in Europe. 
BORDURE, in heraldry, a cutting off 
from within the escutcheon all round it 
about ith of the field, serving as a difference 
in a coat of arms, to distinguish families of 
the same name, or persons bearing the same 
coat. 
BORE, among engineers, denotes the 
diameter of the barrel of a gun or cannon, 
or rather its whole cavity. 
Bore, square, among mechanics, a square 
piece of well-tempered steel, fitted into a 
handle, serving to widen holes, and make 
them perfectly round. 
BOREALIS. - See the article Aurora. 
BORELLI (J. Alphonso) a celebrated 
philosopher and mathematician, born at Na- 
ples the 28th of January, 1008. He was pro- 
fessor of philosophy and mathematics in some 
of the most celebrated universities of Italy, 
particularly at Florence and Pisa, where he 
became highly in favour with the princes of 
the house of Medicis. But having been 
concerned in the revolt of Messina, he was 
obliged to retire to Rome, where he spent 
the remainder of his life under the protec- 
tion of Christina, Queen of Sweden, who 
honoured him with her friendship, and by 
her liberality towards him softened the ri- 
gour of his hard fortune. He continued 
two years in the convent of the regular 
clergy of St. Pantaleon, called the “ Pious 
Schools,” where he instructed the youth in 
mathematical studies. And this study he 
prosecuted with great diligence for many 
years afterwards, as appears by his corres- 
pondence with several ingenious mathema- 
ticians of his time, and the frequent mention 
that has been made of him by o tilers, who 
have endeavoured to do justice to his me- 
mory. He wrote a letter to Mr. John Col- 
lins, in which he discovers a great desire 
and endeavours to promote the improve- 
ment of those sciences ; he also speaks of 
his correspondence with, and great affection 
for, Mr. Henry Oldenburgh, Secretary of 
the Royal Society ; and Dr. Wallis ; and of 
the then late learned Mr, Boyle, He died 
