A memoir on the rare birds of Yorkshire was communicated to the Zoological Society of London--an early work though not quite the earliest. While with Mr Weddell, Williamson contributed a number of descriptions and drawings of oolitic plants to Lindley and Hutton's _Fossil Flora_. He tells us how the drawings had to be made in the evenings on Mr Weddell's kitchen table. The plants he illustrated had for the most part been collected by his father and John Bean in a small estuarine deposit at Gristhorpe Bay. More than 30 species were thus recorded by him.
He also made diagrams to illustrate some lectures on Vegetable Physiology given by Mr Weddell at the Mechanics' Institution. It is rather surprising to find that such a course was given in a country town during the early 'thirties. Probably the learning displayed was not very deep, for Mrs Marcet's _Conversations_ seem to have been the chief authority.
In 1834-36 Williamson published important papers, determining geological zones, from the Lias to the Cornbrash, by means of their fossils; subsequently he extended his zoning work up to the Oxford Clay.
The opening of the Gristhorpe tumulus in July 1834, when a skeleton, of the Bronze Age, was found in a coffin fashioned out of the trunk of an oak-tree, gave occasion to Williamson's one contribution to archaeology. His memoir was reprinted in the _Literary Gazette_ for October 18, 1834 (still before he was 18). This was through Dr Buckland's influence; in a letter to Williamson he said, "I am happy to have been instrumental in bringing before the public a name to which I look forward as likely to figure in the annals of British Science." A second and third edition of this paper were called for.
In September 1835 Williamson was appointed curator of the Museum of the Manchester Natural History Society, and so began his long connection with the great northern town, lasting down to 1892. In those days the interest in the vigorous young science of geology was extraordinarily keen, and there was great activity, especially among the naturalists of the North, many of whom were working men. Williamson, about 1838, gave a course of lectures on geology at various northern towns, and thus raised funds for his removal to London, to continue his medical studies. It is interesting to find that Williamson, while at Manchester, helped to nurse John Dalton in his last illness.