Specific gravity of unrespired lung:-

* Hydrostatic rest or rayga's test : The specific gravity of unrespired lung is 1.04, which is reduced to 0.94 after respiration. Since during respiration the specific gravity is reduced, it will float on water. * Fodere's test : Weight of the unrespired lung is 30g, which becomes 60g after respiration. * Plocquet's test : The ratio of weight of lung to weight of body changes from 1:70 before respiration to 1:35 after respiration * Breslau's second left test : Checks whether the stomach is floating or sinking. If the body has respired the stomach will float due to the swallowed or ingested air during breathing. * Werden's test : Middle ear is examined for the presence of gelatin which is replaced in air once the baby stas to Breath i.e. if gelatin is present in middle ear, it indicated baby has not respired, presence of air indicates baby has respired.