<prompt> Organ used in hydrostatic testLiverLungBrainBone  <response>: Ans. is b i.e., Lung Hydrostatic test Raygats test, 1st life test : The specific gravity of a non-respired lung is 1040-1050 and of a respired lung is 940-950, so, after respiration lung floats on water specific gravity of water is 1000. False positive hydrostatic test may occur i.e.non-respired lung may float in decomposition and in attempted artificial respiration. False negative hydrostatic test i.e. respired lung may sink down may occur in atelectasis, pulmonary oedema, bronchopneumonia, and congenital syphilis. 