1. The author has made researches, in summer, autumn and winter, of the quantitative variation, following the time after death, of the non-protein nitrogen in bones and cartilages, and the anorganic phosphoric, sulphuric and nitric acid in brains, lungs, livers, kidneys and spleens of rabbits. 2. Each quantities of the non-protein nitrogen in bones and cartilages increase following the time for a certain period after death. The quantities of the anorganic acids in these five organs increase similarly following the time after death, and then decrease after a certain period. 3. The author has proved that the disintegration of dead bodies is more speedy 8-11 times in summer and 3-4 times in autumn than in winter.