This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
Borax has some stimulating effect upon the uterus, as shown by its increasing contraction during labor; it has been used in lingering cases, though generally combined with ergot and cinnamon; it is nauseous in taste. Borax has been given also in amenorrhoea, with or without aloes, and in dysmenorrhoea with belladonna, but is not in general use. Since this is the only soda salt that acts upon the uterine system, it probably does so through the boracic acid.