If you drink milk, this takes the place of some of the water and gives you food as well. It is both drink and food; and a very good food for children it is, too. You know, babies can live on it because it has everything in it to make them grow. Do you know why it is that people are so careful nowadays about having milk and drinking-water very clean? It is because they have found that the tiny plants, called germs, that make people sick are often carried about in these drinks. A disease called _typhoid fever_ is carried in this way. Fifty years ago, cities and towns used to be very careless about where they got their water supply, and would often take it out of streams into which other cities emptied their sewage. Now, however, they are much more particular; and the health officers, or Boards of Health, are insisting that public water supply, such as is brought into our houses in pipes, shall be taken either from some spring or deep-flowing well, or from a stream or lake up in the hills, into which no drainage from houses or farmyards, and no dirty water from factories, empties. [Illustration: A PIPE FOR THE CITY WATER SUPPLY This pipe is laid for many miles to bring water from the distant hills.] We are still, however, far from being as careful as we should be about this; and I am sorry to say that America has had more deaths from typhoid fever than any other civilized country. Germany, which, of all countries in the world, is the most particular about keeping its water supply pure, has the fewest deaths from this cause, in proportion to its population--scarcely one fifth as many as we have. Therefore, by taking proper care, it would be quite possible to prevent at least two thirds of our nearly 400,000 cases of typhoid fever and 35,000 deaths from typhoid, every year. It is not only cities and towns that ought to be careful of their water supply. In fact, now, out on the farms and in the healthy country districts, the death rate from typhoid fever has actually become higher than it is in our large cities. The main cause of this is the custom of digging the well in such a place that the waste water thrown out from the house, or the drainage from the barnyard or the pigpen or the chicken-house may wash into it, soaking down through the porous soil. Far more typhoid fever now is spread by means of infected well water than by any other means. Most dangerous of all is the leakage from the privy vault; as, by this means, the germs of typhoid fever and other diseases that affect the food tube and digestion may drain through the soil till they reach the drinking water in the well. These dangers can be avoided either by having the well dug at some distance from the house and in higher ground, or by having the drainage from the house, barns, and out-buildings piped and carried to a safe distance from the well.