rous
borax into sodium chloride (W. Ramsay and E. Aston) and from analysis
of the bromide and chloride (Sainte-Claire Deville); the values
obtained ranging from 10.73 to 11.04. Boron can be estimated by
precipitation as potassium fluoborate, which is insoluble in a mixture
of potassium acetate and alcohol. For this purpose only boric acid or
its potassium salt must be present; and to ensure this, the borate can
be distilled with sulphuric acid and methyl alcohol and the volatile
ester absorbed in potash.

BOROUGH [BURROUGH, BURROWE, BORROWS], STEVEN (1525-1584), English
navigator, was born at Northam in Devonshire on the 25th of September
1525. In 1553 he took part in the expedition which was despatched from
the Thames under Sir Hugh Willoughby to look for a northern passage to
Cathay and India, serving as master of the "Edward Bonaventure," on
which Richard Chancellor sailed as pilot in chief. Separated by a storm
from the "Bona Esperanza" and the "Bona Confidentia," the other two
ships of the expedition, Borough proceeded on his voyage alone, and
sailing into the White Sea, in the words of his epitaph, "discouered
Moscouia by the Northerne sea passage to St Nicholas" (Archangel). In a
second expedition, made in the "Serchthrift" in 1556, he discovered Kara
Strait, between Novaya Zemlya and Vaygach island. In 1560 he was in
charge of another expedition to Russia, and, probably in 1558, he also
made a voyage to Spain. At the beginning of 1563 he was appointed chief
pilot and one of the four masters of the queen's ships in the Medway,
and in this office he spent the rest of his life. He died on the 12th of
July 1584, and was buried at Chatham. His son, Christopher Borough,
wrote a description of a trading expedition made in 1579-1581 from the
White Sea to the Caspian and back.

His younger brother, WILLIAM BOROUGH, born in 1536, also at Northam,
served as an ordinary seaman in the "Edward Bonaventure" on her voyage
to Russia in 1553, and subsequently made many voyages to St Nicholas.
Later he transferred his services from the merchant adventurers to the
crown. As commander of the "Lion" he accompanied Sir Francis Drake in
his Cadiz expedition of 1587, but he got himself into trouble by
presuming to disagree with his chief concerning the wisdom of the attack
on Lagos. He died in 1599. He was the author of _A Discourse of the
Variation of the Compas, or Magneticall Needle_ (1581), and some of the
ch