Accounts or invoices in business are usually made out on ruled and printed forms, and are headed with the address of the seller. After that come the names of the buyer and seller, thus:— _MISS RACHEL O’FLINN, Bought of LEIGH, GOLDHAWK, AND STILL._ Or the wording may be, _MISS RACHEL O’FLINN, To LEIGH, GOLDHAWK, AND STILL_, which mean that Miss Rachel O’Flinn is _debtor to_ the firm named, the word “debtor” being dropped in practice. Below the names of the parties the terms of sale are sometimes put: “_Nett Cash_” or “_Cash in 14 days_,” or “_Accounts rendered monthly_,” or whatever the conditions are. Then follow the particulars of the goods sold, the dates when they passed into the hands of the purchaser being put in the left hand margin. People who have any money transactions at all, and do not wish their affairs to get into hopeless confusion, must keep books of some sort—that is to say, they must adopt a plan of writing down their transactions in regular order for easy reference. It may be a primitive method or a very elaborate one—that depends on the nature and requirements of the business—but some system there must be, and of book-keeping in at least its general principles every business woman should make a study. By its means we gain an exact knowledge of how we stand, we see what comes in and what goes out, how much we owe and how much other people owe us, and whether we are putting any of our money into bags with holes. There are many good books published on the subject of book-keeping, and by all means study the best treatise you can get; but better than all books is actual practice. The experience of keeping an account of one’s own transactions for a week gives more insight than all the books that have ever been written. In a book, things seem sometimes exceedingly puzzling, whilst in reality they are simple enough. The main fact to be grasped in book-keeping is the distinction between debtor and creditor; you must get it well into your head that _the person or thing represented by an account is “debtor to” what he, she, or it receives, and “creditor by” whatever he, she, or it gives or parts with_. The simpler business books are the better, so long as they answer the purpose for which they are intended. They must be clear to the person who keeps them, and clear also to any who have to consult them. The utmost care should be taken with them, so as to have no blotting, no scraping out of figures, and no tearing out of leaves. There are two ways of keeping books, known as single entry and double entry. Single entry is called so because each item is entered only once in the accounts of the ledger, which is the principal book. In double entry, on the other hand, it is entered twice, to the debtor side of one account and to the credit of some other account.