Diuresis used to increase urine output and decrease extracellular fluid volume. Substances in the circulation can also increase the amount of circulating fluid by increasing the osmolarity of the blood. This has the effect of pulling water from the interstitial space, making more water available in the blood and causing the kidney to compensate by removing it as urine. In hypotension, often colloids are used intravenously to increase circulating volume in themselves, but as they exert a certain amount of osmotic pressure, water is therefore also moved, further increasing circulating volume. As blood pressure increases, the kidney removes the excess fluid
Water organ these only the one at the Palazzo del Quirinale has survived. Kircher's illustration in "Musurgia universalis" (1650), long thought to be a fanciful representation of a hypothetical possibility, has been found to be accurate in every detail when compared to the organ grotto at the Quirinale, except that it was reversed left to right. There are still traces of the instrument at the Villa d'Este but the mineral-rich water of the river which cascades through the organ grotto has caused accretions which have hidden most of the evidence from view. In the early 17th century, water organs were built in