A potometer measures how factors such as light, temperature, humidity, light intensity and wind will affect the rate of transpiration. The main type of potometer is the 'bubble' potometer shown in Figure Figure 6.
Physicians recommended against the practice because they did not want medicines associated with punishment. A heavy dose of castor oil could be used as a humiliating punishment for adults, especially political dissenters. Colonial officials used it in the British Raj (India) to deal with recalcitrant servants. Belgian military officials prescribed heavy doses of castor oil in Belgian Congo as a punishment for being too sick to work.
1 Rarely, castor oil was to be taken internally as a purgative. 2  Warm castor oil packs applied to the abdomen was the most widely recommended use for castor oil. 3  Castor oil packs were given for a variety of complaints, from breaking up abdominal adhesions, to loosening locked bowels.