The complexing of lanthanum by various anions and weak acids was investigated by observing the light absorption of the complex formed with thenoyltrifluoracetone (TTA). This species showed the properties needed for a satisfactory specgtrophotometric method of analysis.

The basic scheme under consideration in this research on stability of closed-loop of the Mark I machine is one in which a voltage proportional to the magnitude of the rf fields in the cavity acts to control rectifier voltage output. It is recognized that such is not the only scheme for maximization of output which may be conceived, but only what seems to be a logical and direct way of attaining such an objective.