Piperaz. is a synthetic product which was intended to replace Spermin (C2H5N), and was named Dispermine. It was found, however, to be a different body both in chemical and physiological properties. It occurs in well-defined, colourless, acicular crystals (Helbing), or in lustrous tables (J. Gordon); is deliquescent and mostly soluble in water. It readily unites with uric acid, forming a very soluble compound (urate of piperazine). When taken by the mouth it is not entirely oxydised, as part is discoverable unchanged in the urine. John Gordon experimented with Piperaz. and found that a 1-per cent. solution in normal urine at body temperature dissolved to a large extent a fragment of uric acid calculus, and converted undissolved portions to a granular and pulpy condition. The amount of urea is increased in the urine of those taking it; and Helbing (Modern Materia Medica) says it has been used with success in mental diseases, and in a case of lead paralysis with "very remarkable results." J. R. Hamilton, of Hawick (Lancet, December 30, 1893), reports success in treating renal colic with Piperaz.; and Walter, of Odessa (quoted H. W., xxv. 10), cleared up two cases of glaucoma, giving one grain daily in carbonated water, all the symptoms disappearing within three weeks. [After a teaspoonful dose of an effervescing preparation of Piperaz., a patient complained that he was seized with a bad attack of acute gout, that was quite unexpected (Cooper).]