It is essential to the highest economy that the expense account be frequently analyzed, and kept in such condition as to afford at all times data for a classified statement of expenses. This may be done by carrying a large number of expense accounts in the general ledger, such as salaries, stationery, etc.; but this method tends to complicate the trial balance. For some years past, many banks and other institutions with large expense accounts have made it a practice to charge all expense items to one account, and keep an expense analysis book, which provides for a more elaborate classification than can conveniently be carried in a ledger. Form 41 gives a page from such a book, which is of the loose-leaf form and well adapted to real estate offices.