Nature has a good reason for everything she plans.
It is asserted by physiological chemists that saliva, taken from the mouth and kept at normal temperature, will dissolve breads and similar foods and convert the starch in them into maltose, glucose or sugar. The converted form is that which is suitable for further digestion. Saliva also converts some acids into alkali and readily neutralises all acids.
It is also asserted that saliva does not dissolve some things (proteid substances) nor chemically affect them as visibly as it does starch and acid, but, even if this be true, it is no less essential that the juices provided in the mouth should have an opportunity, through mastication, or, movement about in the mouth, to do what they are able to do in assisting digestion.
Experiment shows that if all foods are submitted to the examination and action of these juices until involuntary swallowing takes place, the results in aiding subsequent digestion are important in promoting healthy nutrition.
Separation, neutralisation, alkalination, saccharidation, of the proteid and carbohydrate elements of common foods and perhaps a partial emulsification of fats are all possible in the mouth and are more easily and quickly done there than inside the body. Much care in Mouth-Treatment is an assurance of economy and safety in Alimentation.
[OBJECTIONS CONSIDERED]
One of the objections usually provoked by the suggestion that all tasteless residue remaining in the mouth after the taste or nutriment has been dissolved out of it should be removed is generally expressed in this wise, "How is it possible to remove refuse from the mouth while eating without appearing disgusting to others at table? You have to swallow things to get rid of them."
This is merely a bugbear prejudice. It has no good reason.