–A witness may also testify to facts mentioned in any such document as is mentioned in section 159, although he has no specific recollection of the facts themselves, if he is sure that the facts were correctly recorded in the document.
Illustration A book-keeper may testify to facts recorded by him in books regularly kept in the course of business, if he knows that the books were correctly kept, although he has forgotten the particular transactions entered. 1161. Right of adverse party as to writing used to refresh memory. –– Any writing referred to under the provisions of the two last preceding sections must be produced and shown to the adverse party if he requires it; such party may, if he pleases, cross-examine the witness thereupon.