Many theories concerning the etiology of eclampsia have been advanced. For certain of them there is more or less experimental and clinical evidence. The treatment, however, remains purely empirical. Each theory has as its basis that the eclamptic seizure is due to toxin developed as the result of pregnancy. As to the origin of this toxin, the authors vary to as great a degree as do the theories. The development of this toxin may be due to:(a) A growing ovum and its metabolic products.(b) Functional changes in the liver resulting from pregnancy.(c) General metabolism being affected during pregnancy with the result that the food stuffs are not cared for properly.(d) The advent of the study of parenteral digestion of foreign protein by specific ferments suggested another possibility that the toxins originate from the detached elements of the placenta as a result of their specific parenteral digestion.The numerous attempts that were made to demonstrate by experiment the presence of this toxin in the blood wer...