What is Book Of Original Entries?

Legal Definition
A book in which a merchant keeps his accounts generally and enters therein from day to day a record of his transactions. McKnight v. Newell, 207 Pa. 662, 57 Atl. 39. A book kept for the purpose of charging goods sold and delivered, in which the entries are made contemporaneously with the delivery of the goods, and by the person whose duty it was for the time being to make them. Laird v. Campbell, 100 Pa. 165; Ingraham v. Bockius, 9 Serg. & It. (Pa.) 285, 11 Am. Dec. 730; Smith v. Sanford, 12 Pick. (Mass.) 140, 22 Am. Dec. 415; Breinig v. Meitzler, 23 Pa. 156. Distinguished from such books as a ledger, into which entries are posted from the book of original entries.
-- Black's Law Dictionary