pH

1909 Minnesota Department of Health, R.N. Barr Library; Librarians Melissa Rethlefsen and Marie Jones This 1910 photograph depicts a portable emergency hypochlorite plant that was property of the Minnesota State Board of Health; Division of Sanitation. The photo presents a general view of the original plant. This is one of a series of instructional photos used by the Minnesota Board of Health to train public health workers. The focus of the images, and the training effort was to promote sound practices involved in protecting potable water supplies from bacterial contamination. The descriptive information accompanying this image referred to a governmental publication outlining the operating instructions for this device. The specific citation is: “Whittaker, H.A.; Hypochlorite treatment of water supplies; portable plant and field equipment for its administration Public health reports, 30:608-18, 1915.