A STUDY OF BLOOD MANUFACTURE 107 



proper digestion of food depends in no small degree upon 

 one's mental state ; worry and disagreeable topics should, 

 therefore, be forgotten so far as possible while one is eating, 

 and the mealtime should be made a season of enjoyment. 



Regular hours of eating are of great importance, for noth- 

 ing more commonly deranges the digestive system than the 

 continual nibbling of food or sweetmeats between meals. 

 One should refrain from vigorous exercise or mental exertion 

 for a half hour or more after eating ; the reason for this will 

 be clear after a study of the blood system. 



Care of the Teeth. Too mugh stress cannot be laid on 

 the importance of caring for the teeth, since decaying 

 teeth are frequently painful, they are always unsightly and 

 are usually the cause of an ill-smelling breath, and they 

 often lead to other derangements of the alimentary canal. 

 Immediately after eating one should brush the teeth thor- 

 oughly on all sides, using warm water and a little castile 

 soap or an alkaline tooth powder, and should make sure 

 that bits of food are not left to decay between the teeth. 

 The frequent use of dental floss or silk to clean the spaces 

 between the teeth is essential. Pins, knifeblades, or other 

 metallic implements, however, should never be used for this 

 purpose. In the process of decomposition to which we have 

 referred, acids are formed that eat away enamel and den- 

 tine, and a cavity when once begun grows rapidly unless the 

 decay is stopped. For this reason alkaline tooth powders 

 are recommended to counteract the possible effects of acids. 

 A dentist should be consulted at least once a year, in order 

 that the " tartar " may be removed and the cavities filled while 

 they are small. The teeth ought never to be used to crack 

 nuts or to pull out nails, for while the enamel is a very hard 

 substance, it is also brittle and can be cracked or broken off 

 by such treatment ; if once lost it will not grow again. 



Adaptation of Foods to Individual Needs. The growing child 

 should be supplied with a simple diet composed of milk, 

 cereals, eggs, bread, and fruits, and parents should exercise 



