Previous impressions of specificity of psychiatric manifestations in relation to particular chemical intoxications have been confirmed by comparisons of the symptoms and signs of two groups of individuals. Nine persons exposed to inorganic mercury had “erethism” and xenophobia in addition to non‐specific features of central nervous system poisoning. Twelve men with heavy exposure to organotins, in contrast to ten men with light or no exposure, more frequently presented an unique alternation between out‐bursts of rage and deep depression, the latter lasting from a few hours to a few days. The more heavily exposed men also had a greater number of non‐specific symptoms from neurotoxins.