A study of lubricants during compression and in finished tablets has shown that, (1) lubricants are confined to the surface and intergranular regions of the finished tablets and do not mix intimately with the contents of the granules, (2) approximately 1 per cent lubricant appeared to give nearly o timum granulation lubricity when applied to the test granulations used in this stucfy, (3) fluid lubricants appeared to flow into tablet voids and unlike solid lubricants did not usually cause significant increase in punch forces when added in increasing amounts if the machine settings and weights of die fill were constant, (4) the addition of lubricants, e. g., ma nesium stearate, to granulations tended to roduce slightly softer tablets and at t8e same time significantly prolonged tablet $isintegration time in the usual concentrations.