Notes of chemistry lectures, more specifically focusing on absorbent earths, given by Professor of Chemistry at Edinburgh, Joseph Black (1728-1799). The lectures are numbered throughout and begin on lecture 49. It is not clear if this is where Dobson began his notes or if there were once more volumes, however the Radford Library's 1877 catalogue only refers to one volume.
The content of the lectures are as follows: (49) forms of calcareous earths, (50) particular qualities of calcareous earths & effects of fire, (51) formation and properties of quicklime and lime water and action of lime upon alkalis, (52) the volatile alkali, (53) explanatory theories of calcareous earths, (54) purgative power of magnesia, (55) investigations into effect of fire on magnesia and why it loses much of its weight, (56) explanation of the nature of lime arising from his experiments relating to presence of fixed air, (57) experiment of the solubility in water of slaked lime with reference to fixed air and mephitic air, (58) experimentation to prove that air breathed by animals, air required to burn things, air arising from fermenting vegetables, and mephitic air are all the same and comments on the qualities of the caustic alkali, borax, and marl.
There are some additional notes quite distinct from Black's lecture notes on ff.91-96 with comments on the method of making common ink, sympathetic ink, Nicolas Lémery's (1645-1715) method to make an artificial earthquake, and different kinds of earthquake.
The volume bears the bookplate of the Radford Library, Saint Mary's Hospital, Manchester, which also indicates that it was allocated the reference number Q131 viz. their 1877 catalogue. The volume has since been referenced H7 B8 as part of an alternative system. There is no pagination and the writing is largely on the recto only.