Published online by Cambridge University Press: 10 July 2009
1. A method is described of using the Adam-Langmuir surface pressure trough for the direct measurement of the spreading power of oils against surface contamination.
2. Pure higher paraffins are non-spreading and pure aromatics have only a small spreading pressure. Commercial grades of oils owe what spreading pressure they have to impurities which are only present in small quantities and can be removed.
3. The spreading power of oil is greatly increased by irradiation of very thin layers of the oil. Even so, only a small fraction undergoes chemical change, the great bulk being recoverable with its original properties.