Gordon reviews the history of forty-five psychiatric patients who have been under his observation for a period of twenty-five years, in an effort to evaluate the precipitating factors initiating their various episodes of emotional illness. The long uninterrupted period of observation gives the material special interest and, according to Gordon, makes for an 'almost mathematically accurate … demonstration of the dynamic forces' underlying the disorders, as well as 'correct inferences with regard to the intimate nature of a given affection, the problems of management and of prevention'. He then goes on to discuss his observations in cases of psychoneurosis, manic-depressive psychosis, schizophrenia, involutional melancholia, 'depression without delusions', and psychosis accompanying mental deficiency. The obervations are all made on a descriptive Kraepelinian basis.