38. Novi Comm. Acad. Sci. Petrop., 5, 175-1/5, 205-37, pub. 1760 = Opera, (1) , 14, 585-617, and Nova Ada Acad. Sci. Petrop., 2, 1784, 36-45, pub. 1788 = Opera, (1) , 16, 34-43.