Heterotrophic bacteria were enumerated from the Seattle drinking water catchment basins and distribution system. The highest bacterial recoveries were obtained by using a very dilute medium containing 0.01% peptone as the primary carbon source. Other factors favoring high recovery were the use of incubation temperatures close to that of the habitat and an extended incubation (28 days or longer provided the highest counts). Total bacterial counts were determined by using acridine orange staining. With one exception, all acridine orange counts in chlorinated samples were lower than those in prechlorinated reservoir water, indicating that chlorination often reduces the number of acridine orange-detectable bacteria. Source waters had higher diversity index values than did samples examined following chlorination and storage in reservoirs. Shannon index values based upon colony morphology were in excess of 4.0 for prechlorinated source waters, whereas the values for final chlorinated tap waters were lower than 2.9. It is not known whether the reduction in diversity was due solely to chlorination or in part to other factors in the water treatment and distribution system. Based upon the results of this investigation, we provide a list of recommendations for changes in the procedures used for the enumeration of heterotrophic bacteria from drinking waters.

In 1996, a nursing committee at an acute care facility organized the first pressure ulcer point prevalence survey for that hospital. In 1996, hospital-acquired pressure ulcers were 90 percent of the predicted prevalence rate; in 1997, the rate dropped to 59 percent of the predicted prevalence and in 1998, to 53 percent of the predicted prevalence. The severity index decreased markedly from 291 (1996) to 98 (1997) then to 62 (1998). These improvements are attributed to the purposeful addition of multidimensional interventions, including best practices and research-based protocols, to prevent and treat nosocomial pressure ulcers.

The preparation of the anhydrous chlorides of the rare earth elements is of considerable interest, since these compounds serve as the starting materials in the preparation of the metals, either directly by electrolysis in the fused state or indirectly by electrolysis in alcoholic solutions with a mercury cathode followed by the subsequent thermal decomposition of the resulting amalgams. The most important methods for the preparation of anhydrous rare earth chlorides previously suggested are : from the metals, by action of dry chlorine, hydrogen chloride, or methyl chloride1 at elevated temperatures; frdm the oxides, by action of chlorine in the presence of a reducing agent,2 by action of hydrogen chloride alone3 or with ~a r b o n ,~ by action of carbon tetra~hloride,~ carbonyl chloride,6 sulfur monochloride vapor7 (or a mixture of sulfur monochloride and chlorine) ,8 by heating with phosphorus penta~hloride,~ by mixing with a slight excess of ammonium chloride and gradually dropping the mixture into a red-hot c r~c i b l e ;~ from the sulfides, by heating in dry hydrogen chloride;1° from the carbides, by heating with chlorine1' or in a current of hydrogen chloride ; I z from the hydrated chlorides, by heating in a current of hydrogen chloride gas,13 by adding ammonium chloride to a solution of the chlorides, evaporating to dryness, and heating in air14 or in a current of HC1, l5 by dehydration in an atmosphere of carbonyl chloride (or a mixture of carbon monoxide and chlorine16), by heating in air and treating the resulting mixture of chlorides and oxychlorides with sulfur monochloride and chlorine or sulfur monochloride, chlorine, and hydrogen chloride mixtures, by extracting the chloride-oxychloride

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