The period of time necessary for some essential oils to separate from water, at various temperatures, was determined. The tests were made with 10 essential oils produced commercially in Brazil, and the temperatures tried varied from 10º C to 80º C in 5ºC steps. Fifty milliliters of the oil under test was added to 350 ml of water in a 500 ml stoppered Erlenmeyer flask to which a thermometer was fitted to permit temperature readings of its contents. The whole flask was shaken for 30 seconds and then set down do allow the oil to separate from the water. The period necessary for separation was clocked from the end of the shaking operation to the time when a definite line appeared between the oil and water layers. Every observation was made three times and the whole experiment was replicated four times, each with a different oil sample. The main conclusion to be drawn from the rate-of-separation curves (see figures) is that lhe time decreases with increasing temperatures. The results also indicated that a better separation occured at the higher temperatures. The average upward velocities of oil droplets were calculated and are given in table 2. A better separation of oil was obtained when the upward velocities were greater than the downward velocities. The former concerns the. rising of oil droplets and the latter, the stream of the water moving down to the outlet pipe fitted to the bottom of the separating can. In many common field distilleries, some oil carry-over can be easily noticed because the regular separating cans are not large enough to hold the condensate flow during the time necessary for a good separation of the oil. Moreover, the temperature is not kept high enough to permit complete separation at the rate of flow the mixture of water and oil passes through the separating can.