Will books are one of the best ways to determine family relationships in genealogy research. Your research is not complete unless you have looked at wills.
This volume contains entries from Essex County Will Book No. 7, 1743-1747 beginning on page 324 and ending on page 533, May 21, 1745 through May 20, 1747; and Essex County Will Book No. 8, 1747-1750 beginning on page 1 and ending on page 119, June 16, 1747 through December 20, 1748. Originally published in 1991, reprinted in 2016.