To exert an actual germ-destroying effect on the bacterial content of the utensil, resort must be had to boiling or steaming. To treat utensils so as to render them wholly germ-free would be impractical under ordinary commercial conditions, as it would consume too much time, although with proper apparatus, this process is not impossible, but it is well within the limits of practicability in factory treatment to apply steam for a short period of time. Where cans, pails and such utensils, are steamed for a minute or so after being thoroughly cleaned, the germ content is greatly reduced. In a series of tests by Harrison, the germ content of a set of cans cleaned in an ordinary way was 442,000 bacteria per cubic centimeter in 100 cubic centimeters of wash water; in a set washed in tepid water and then scalded--the best farm practice--it was 54,000 per cubic centimeter, while in cans carefully washed and then steamed for 5 minutes, it was reduced to 880 per cubic centimeter. It would not be worth while to institute measures that would accomplish the destruction of this small residual content. The use of steam, therefore, is of great service in eliminating bacterial life in all utensils. In apparatus of at all complicated design, it is absolutely necessary. Of course, ordinarily, steam can be applied only at the factory, as the farm does not usually afford facilities for its easy generation. This fact has led in some cases to the adoption of the method of cleaning and sterilizing the cans at the factory rather than to await their arrival at the farm. This custom is most frequently followed in milk supply plants. It is also very important in cleaning dairy utensils to see that they are rapidly and thoroughly dried after being washed and steamed. As pointed out above, the short period of steaming that can be followed in practice does not kill all the bacteria. If moisture is retained, conditions permit of the growth of the undestroyed organisms. Tests made on glass milk bottles showed that considerable growth occurred in the condensation water even after quite thorough sterilization. Some of the devices used for the sterilization of such utensils as milk cans are so arranged that, after steam has been introduced, hot air is passed into the can until it is thoroughly dried. Other utensils such as cloth strainers become sources of contamination unless the articles are thoroughly and quickly dried after cleaning. In a general way, it may be said that whenever a utensil is so constructed and in such a condition that every portion of its surface can be reached by a cloth or a brush, it can be kept in a sanitary condition. But whenever any portion cannot be thus reached, whether it is an angle or a seam in a pail or can, the interior of the separator bowl, or in the pipes used for conducting milk, contamination is certain to result from such places, unless extreme care is taken to destroy the bacteria therein by steaming.