The water excretion test of adrenal function as described by Robinson, Power and Kepler1 has been used in the diagnosis and exclusion of adrenal insufficiency. The test is made in two parts*. Part 1 consists of a comparison between the volume of urine excreted during the night and the largest volume of a single hourly specimen supplied in the forenoon. In the original description of the test it was stated that "if the volume of any single hourly specimen provided during the morning is greater than the volume of urine provided during the night, the response to the test is negative, that is, such a response indicates the absence of Addison's disease." It was further stated that if part 1 was negative, part 2 need not be carried out. However, in our study both parts of the test were completed in all instances regardless of the results obtained in part 1, principally because we wished to verify the findings advanced by Robinson, Power and Kepler.
In the 194 consecutive tests comprising this study the results obtained were divided into four groups. Group 1 included tests in which both parts gave negative results. Group 2 included tests in which part 1 was negative and part 2 positive. Group 3 included tests in which part 1 was positive and part 2 negative. Group 4 included tests in which both parts gave positive results.
Group 1 —Part 1 and part 2 negative, 113 tests in 112 cases. In 111 of 112 patients the. . .