FARM MANAGEMENT 41 



raw, yet such precautions should be exercised. Experiments have 

 demonstrated that butter washed with sterile, or pasteurized water, 

 keeps much better than if washed in ordinary water. 



Cisterns. A well built cistern, carefully looked after, is proba- 

 bly the best water supply the people of some sections can obtain. No 

 contamination can get into this supply except through the top of the 

 cistern, and if the top is kept closed tightly, any other contamination 

 must come through the down spouts from the roof. If the first water 

 from every rain is not allowed to run into the cistern and the water 

 which is caught is made to pass through a cleanable screen, made of 

 fine wire gauze, the cistern will be kept in a good, pure condition. 

 Where cisterns are used, all birds should be discouraged from con- 

 gregating about the home ; they will pollute any cistern. Some kind 

 of pump, preferably a chain bucket pump since it tends to prevent 

 the woody taste that is characteristic of rain waters should be used 

 to draw the water. Drawing water by means of a rope and bucket 

 will introduce filth, and the cistern must be opened, and, at times, 

 will be negligently left so. The cistern should be cleaned out oc- 

 casionally. (Okl. S. B. 67.) 



In alkali sections of the country it is frequently difficult to get 

 potable water except by distillation. 



Ice for Household Use. The purity and wholesomeness of the 

 ice supply has become very important because of the increasing use 

 of ice for many purposes in the farm house. The consensus of 

 opinion is that natural ice formed to a reasonable depth is compara- 

 tively pure under ordinary circumstances, but that it is very likely 

 to be contaminated if it freezes to the full depth of the shallow pond, 

 or stream, or if it is flooded with surface water. In general there are 

 a great many conceivable ways that ice and ice supplies may become 

 affected. The danger from many of these causes of infection may, 

 however, be so remote or so infrequent as to hardly merit notice. 

 There are, however, a few dangers associated with the formation of 

 natural ice and the harmfulness of ice supplies as now generally 

 practiced. The first of these dangers is the one due to the harvesting 

 of ice from polluted sources. This ice may be taken from ponds or 

 rivers which have been polluted by sewage and may contain the 

 germs of typhoid fever and other diseases. Secondly, ice may be- 

 come contaminated during the period and operations of harvesting 

 by filth which may have come from infected sources. The hands and 

 feet of laborers or the hoofs of horses may be channels by which 

 infection may be transmitted to the ice even after it has been taken 

 from the water, and notwithstanding the purity of the water. 

 Thirdly, ice may become infected from surface drainage from the 

 adjacent lands during thaws. The water which has flowed over in- 

 fected fields that may have been fertilized or otherwise infected may 

 be carried onto the ice and settle and be frozen into it. Finally, ice 

 may become infected from the exposure and handling incident to 

 distribution of it. This may be by far the most serious mode of in- 

 fection, for it leaves the time interval between infection and trans- 

 mission too short for any counteracting influence of cold to be exerted. 



