ALLANTOIN is found in the allantoic liquid of the cow, and in the urine of sucking calves. It forms glancing prisms of neutral reaction slightly soluble in water. It can be obtained by the oxidation of uric acid by means of lead dioxide, manganese dioxide, ozone or potassium permanganate, and has been synthe sized by E. Grimaux by heating one part of glyoxylic acid with two parts of urea (q.v.) for ten hours at too° C. It is the diurcide of glyoxylic acid, with the formula