The professorial system of divided work, which assigns special departments of learning to supposed experts, had not superseded in King’s College the method of regency which prevailed in the early history of all the universities of Scotland. The regent was intrusted with the education of his pupils from the first matriculation to graduation; or when Latin, Greek, and pure mathematics were each provided for professorially, regents in philosophy each taught in successive sessions the various branches of natural and physical science, and of moral and metaphysical philosophy. This system was followed in all the Scottish universities until last century. It was modified by the Commission of 1690, which ordained that, besides a separate professor of Latin, one of the four regents should profess Greek only, and take charge of undergraduates in their first year. By about the middle of the century ‘regenting’ was wholly abolished in four of the five Universities—in Edinburgh in 1708, in Glasgow in 1727, in St. Andrews in 1747, and in Marischal College and University in 1753. But in King’s College the various branches of Philosophy, natural and moral, were still regented when Reid began to teach. He was thus required to teach mathematics and the sciences of matter, as well as psychology and moral philosophy. He thus gave lectures on the philosophy of mind only every third year. One of the other two years was given to natural history and the easier parts of physical science; the second to mathematics and natural philosophy. During 1751-52, which was his first session, Reid as regent taught natural philosophy to undergraduates of the third year; in the following winter the same students, in their fourth year, were still in his charge. His full sequence, accordingly, did not commence till 1753-54, when for the first time he took the second class, consisting of those beginning philosophical studies. So his successive three years courses ran thus:—1753-56, 1756-59, 1759-62. In the last year of each course, as ‘promoter,’ he presented his undergraduates to receive the Master’s degree, and also delivered a graduation thesis. His theses (still extant in manuscript at Birkwood) were in Latin; they deal chiefly with the methods and human conditions of philosophical inquiry. Two-thirds of Reid’s lectures at King’s College were in this way concerned with natural history and applied mathematics: only one-third was given to the central object of his intellectual interest at New Machar. I have examined a manuscript volume of notes of the lectures in ‘Natural Philosophy’ which he gave in 1757-58. They comprehend, after an introductory exposition of the province and methods of physics, the laws of motion, astronomy, optics, electricity, and hydrostatics. The notes show that Reid was well abreast of the physical science of his time.