B This letter corresponds to the second symbol in the Phoenician alphabet, and appears in the same position in all the European alphabets, except those derived, like the Russian, from medieval Greek, in which the pronunciation of this symbol had changed from b to v. A new form had therefore to be invented for the genuine b in Slavonic, to which there was, at the period when the alphabet was adopted, no corresponding sound in Greek. The new symbol, which occupies the second position, was made by removing the upper loop of B, thus producing a symbol somewhat resembling an ordinary lowercase b. The old B retained the numerical value of the Greek β as 2, and no numerical value was given to the new symbol. In the Phoenician alphabet the earliest forms are or more rounded . The rounded form appears also in the earliest Aramaic (see Alphabet). Like some other alphabetic symbols it was not borrowed by Greek in its original form. In the very early rock inscriptions of Thera (700-600 B.C.), written from right to left; it appears in a form resembling the ordinary Greek λ; this form apparently arose from writing the Semitic symbol upside down. Its form in inscriptions of Melos, Selinus, Syracuse and elsewhere in the 6th and 5th centuries suggests the influence of Aramaic forms in which the head of the letter is opened, . The Corinthian , and (also at Corcyra) and the of Byzantine coins are other adaptations of the same symbol. The form which it takes in the alphabets of Naxos, Delos and other Ionic islands at the same period is difficult to explain. Otherwise its only variation is between pointed and rounded loops ( and ). The sound which the symbol represents is the voiced stop made by closing the lips and vibrating the vocal chords (see Phonetics). It differs from p by the presence of vibration of the vocal chords and from m because the nasal passage as well as the lips is closed. When an audible emission of breath attends its production the aspirate bh is formed. This sound was frequent in the pro-ethnic period of the Indo-European languages and survived into the Indo-Aryan languages. According to the system of phonetic changes generally known as "Grimm's law," an original b appears in English as p, an original bh as b. An original medial p preceding the chief accent of the word also appears as b in English and the other members of the same group. It is not certain that any English word is descended from an original word beginning with b, though it has been suggested that peg is of the same origin as the Latin baculum and the Greek βάκτρον. When the lips are not tightly closed the sound produced is not a stop, but a spirant like the English w.
In Late Latin there was a tendency to this spirant pronunciation which appears as early as the beginning of the 2nd century A.D.; by the 3rd century b and consonantal u are inextricably confused. When this consonantal u (English w as seen in words borrowed very early from Latin like wall and wine) passed into the sound of English v (labio-dental) is not certain, but Germanic words borrowed into Latin in the 5th century A.D. have in their Latin representation gu- for Germanic w-, guisa corresponding to English wise and reborrowed indirectly as guise.
The earliest form of the name of the symbol which we can reach is the Hebrew beth, to which the Phoenician must have been closely akin, as is shown by the Greek βῆτα, which is borrowed from it with a vowel affixed.