It is necessary to give the teeth a reasonable amount of regular use. Cultivate the habit of eating zwieback, hard crackers or other hard food substances that require real vigorous chewing. If this is difficult, then make a habit of exercising the teeth in some way. The idea suggested in the illustrations accompanying this chapter will be found of value, though any method can be recommended that serves the same purpose. Do not, however, depend upon the chewing of gum for hours each day as a means of exercising the teeth. Chewing a hard gum for a few minutes after a meal might be of advantage, but continual gum- chewing wastes and weakens the digestive elements of the saliva. In other words, if you sit down to a meal after chewing gum for two or three hours, the saliva that you mix with your food will not have the normal digestive elements. One might say that the "strength" of the saliva has been lost while chewing gum. If your teeth are decayed the offending members should be removed or the cavities filled. It is always wise to retain every tooth you can until extraction is practically compulsory. Decayed teeth should be filled promptly. As long as a tooth can be filled it should not be extracted. A good dentist should be consulted at frequent intervals. If tartar has collected on the teeth, it should be removed by a competent dentist. One good method of keeping the teeth free from tartar is to rub the gums and teeth daily with table salt containing considerable grit. Dampen the finger, place a quantity of table salt thereon and then rub the teeth where they meet the gums. Make the process sufficiently vigorous to rub off any tartar that may have accumulated. The mouth should be rinsed with moderately warm water immediately after this process to remove the salt. Any good tooth wash that is sold in the form of paste can be used instead of salt for this same purpose. This rubbing process is of more value to strengthen the gums and to cleanse the teeth than brushing the teeth with an ordinary tooth brush. Tooth brushes, however, are valuable and should be used morning and evening. In caring for the teeth the following plan is suggested: Soon after rising rinse the mouth out thoroughly with a mild antiseptic tooth wash; soap, or salt and water, is fairly good if nothing better can be obtained. Plain water will also serve the purpose. Lemon juice to which considerable water has been added, also makes a good mouth wash. Orange juice can also be recommended.