A lady once received a telegram containing disastrous news just as she was finishing a meal. Up to that time she had never known what indigestion was, yet for the next couple of days she suffered from it in a most acute form. The nervous shock had thrown the stomach out of order, inhibiting the secretion of gastric juice. We cannot help troubles of this sort, but it is only once in a lifetime, perhaps, that we get a message of that sort during the progress of a meal. It is to be feared, however, that it is of almost daily occurrence for some people to sit down to table worrying over the business of the day. And the accumulated effects of these minor disturbances may in the long run prove more detrimental than one big one. Conversely, the stomach has an equally potent influence over the nervous system. Everyone knows that when their digestion is out of order, and they are feeling uncomfortable or bilious, their heads are not so clear as usual. And with this there is a feeling of langour and irritability, and a difficulty in doing work efficiently. This is because the body fails to get its proper supply of nourishment, and also because it is poisoned at the same time. In order to understand the manner in which this is brought about, it is necessary to know something as to the events which are taking place throughout the body every moment of our lives. [Sidenote: Combustion and elimination.] When food is taken it is first digested and then passes out of the stomach, and is carried by means of the circulation to all parts of the body. It nourishes the various tissues, replacing the loss which is constantly going on. For there is throughout the whole system a process corresponding to combustion, and this combustion, like the furnace of an engine, is the source of our energy. As in an ordinary fire, ashes are produced in the form of waste matter of a poisonous nature. This waste must be removed from the tissues, else it interferes with the process, as a neglected fire is apt to become choked up and burn badly. This removal is also accomplished by the circulation. In any community you may see on any ordinary working day two sets of carts, those belonging to tradesmen which distribute groceries and vegetables, and the scavengers’ carts which gather up the refuse. The same processes go on in the human body, with the difference that in this case the same agency which brings the supplies also carries away the waste.