Raygat's test is based on:
Hydrostatic test/ Raygat's test: Principle: Specific gravity of lung before respiration is 1.04-1.05 and it becomes 0.94-0.95 after respiration. This makes the respired lung to float. Procedure: Dissect out the fetal lungs & Put into a trough of water and observe. Liver is used as control Inference: If they sink--unrespired lung. If they float--remove them from water, cut into small pieces and then squeeze or compress firmly between sponges, and again put into water. If they sink--unrespired lung. If they float--respired lung. Explanation: Floatation observed for second time is because of residual air that remains in the lungs which cannot be squeezed out by pressing, if the fetus has breathed after bih.
Weight of lung
Specific gravity of lung
Consistency of lung
Volume of lungs
Infant deaths & child abuse