However, as this story will be read by inhabitants of unfiltered municipalities and towns, whatever danger and comfort can accrue from non-filtration or filtration of water will be evident after a glance at this attempt to bring it to your mind. Just as this goes to press we see in the paper that a western town of Salem has seven hundred and eighty cases of typhoid in a population of ten thousand. Here is food for thought! Hundreds of towns (one firm alone has installed about 163 plants) in the United States have municipal filtration plants. Some even oxygenate the water by fountaining it esthetically skyward and allowing it to entice to itself oxygen (from the free air), by which it gets life and polish and becomes refreshing. Some towns chlorinate the water supply. When water is chlorinated, minute quantities of chlorine are added which absolutely destroy the germs in the water, but do not alter its chemical or physical characteristics in the least. The difference between a water that has been chlorinated and one that has not been so treated is that in the first case the germs are destroyed, but in the second case they remain in the water to cause possible disease. This process is rarely used in the home as the control is too difficult. But in the case of the elaborate residence with large incumbencies in the way of model farms, dairy, stables, machine shops, etc., it is used. Also the smallest plants are used in the case of large swimming pools in and out of fine residences, where, of course, the water has been found to be bacterially degenerate and where the work of purification is not done by a benign municipality. To get to the roots of the matter you want water (you don’t care what the high-browed engineer does to it) to be: 1. Colorless. 2. Tasteless. 3. Odorless. 4. Free from suspended matter. 5. With enough oxygen gas to make it refreshing and give it life. 6. Without germs or food for germs. What you want to keep out: 1. Suspended impurities: vegetable, animal (such as the fish), mineral, microscopical algæ (what you see on the stagnant waters), infusoria, etc. 2. Dissolved impurities. 3. Disease germs: typhoid, cholera, etc. What you must demand in a filter: 1. All the above. 2. Durability. 3. Simplicity of management. 4. Nearest approach possible to self cleaning. (The uncertain human element makes many a good filter fall down.) These four things are essential to the longevity of the filter and to you, if you inhabit filterless vales. Another thing suggested by the fourth article of faith above is the care of the filter. If you have a maid you can’t be sure in what state the filter is, unless you keep close watch or have constant inspection by a service bureau. Slight danger from the nearly self cleaning filter can by care be entirely eliminated. But only with care.