The Index will appear when you click on the Book. You can search by Word, Category, or Date; by Word: Click on an alphabet card on the left to go to that letter; by Category: Select one of the 6 Categories on the left; by Date: Click on a century of your choice.  Next, click on an entry under the bold key word or date, and then click "Lookup", or double click on the entry, and the original screen will reappear with the chosen entry.  You can also access the Index by clicking on a bold key word in the text of an entry (you'll find yourself in the Word search), or by typing a key word on the keyboard, and then pressing "enter", at any time.  You can quit the Index by clicking "Cancel".  Each time you leave the Index, it will save the position of your last entry choice. 