If a well is near an outhouse or stable, or a place where cattle are kept, the water that filters through this earth will carry with it germs from these places. A well should always be on higher ground than any outbuildings. It should be some distance from the house, and no slops or anything emptied from the house should be put near it. No drainage of any kind should run near it. In the city of Pittsburg, in the United States, some years ago, there was an epidemic of typhoid fever. Many thousands of people died, and at last the legislature of Pennsylvania appointed a committee to investigate the cause of the epidemic. This committee began to study the source of the city water supply. They traced it far up the mountains, many miles away, until they found a certain little stream emptying into a large river which supplied the city. Living on the banks of this stream was a family where there was a case of typhoid fever. The slops from the house had been thrown into the stream and had so poisoned the water that thousands of people in far-away Pittsburg died of typhoid fever. In Manila there was once a great cholera epidemic, during which more than thirty thousand Filipinos in the city and province of Manila died; many Spanish people died also. During the worst of the epidemic the death rate was at least a thousand every day. But only one Englishman died, and it is said that his death was due to his own carelessness in drinking impure water. If everybody in the city had boiled and filtered the drinking water, as the Americans and the English did, nearly all of these thirty thousand people would have escaped death. What has been said of the impurities collected by water passing through the earth is especially true of the water which supplies Manila. The ground all about the city has been so long occupied by large numbers of people, the drainage has been so poor and so many impurities have been cast out, that the soil for a great distance around the city is a mass of decay. To stir up the earth, as when digging and laying pipes, makes the men who do it feverish and often ill, because of the gases rising from the soil. We may judge from this how bad the water must be that drains through the earth and is collected in the wells of the city. Even the water in the Carriedo water pipes cannot be said to be pure. It comes from a river far from the city. On the banks of this river are many native villages, and the people throw all sorts of refuse into the stream. They wash their clothes in it, and bathe themselves, their horses, and their carabaos there. For this reason the water should be purified before we drink it.