Our knowledge concerning vitamin C has made remarkable progress recently. On the other hand, in the surgical domain, especially in case of acute peritonitis, known as one of the prineipal surgical disease, we have very little or no literature on this subject at home and abroad. So the author performed the following experiments witn regard to the hourly change of vitamin C content in the suprarenal gland of guinea-pigs, suffering from acute peritonitis through artificial infection of bac. coli. For the quantitative determination of vitamin C, strict care was taken to avoid harmful factors, which make the results uncertain, eg. only male guinea-pigs (400-500) were used, and the "methylenblue method" after Martini and Bonsignore was adopted, which Ammon and Hinsberg had recommended. As a control, he took preliminary experiments on the effect of starvation to the vitamin C content and confirmed that it diminished as in the case of scurvy. Then in the case of acute peritonitis, this decrease was much more pronounced than that of both former cases. At the same time, he measured variations of the weight of this organ and confirmed that vitamin C was relatively richer in the smaller organ of normal animal and that the vitamin C content and the weight of the organ were in inversed proportion in some cases of peritonitis. Also he observed that the organ of guinea-pigs was generally larger in the left side than in the right. From the fact that the vitamin C content in the suprarenal gland of guinea-pigs, though it diminished as the time passes through starvation, showed a remarkable decrease in the case of peritonitis, it may be concluded that there exists an intimate relation between the inflammation and vitamin C, so far as other conditions are constant.