Critical temperature, critical pressure, and vapor pressure measurements have been performed on seven compounds by a flow method with ultralow residence times. These compounds along with their Chemical Abstract Services Registry numbers are as follows: 2-phenylethanol (60-12-8), 1-tert-butoxy-2-propanol (57018-52-7), 2-propene-1-ol (107-18-6), 1-dodecanethiol (112-55-0), thioanisole (100-68-5), naphthalene (91-20-3), and triacontane (638-68-6). While accurate vapor pressure data are included for triacontane, this compound proved too unstable to directly determine the critical constants using this apparatus. Accurate vapor pressures, critical temperatures, and critical pressures are included for the other compounds.