As his power of walking failed him, the professor found much solace in music, and sweet snatches of melody were carried across his old-fashioned garden to the ears of passers-by. He played beautifully, and his wife, who was a niece of Colonel Scott of Gala, added greatly to the charms of their musical parties. It is said that they were the first to shock the people of Aberdeen by playing secular music on Sunday.
To the Aberdonians, however, he gave a more serious cause for complaint—William Gregory was of a singularly childlike and trustful disposition, and he was intensely interested in the occult science of Spiritualism; the result was that he became the patron of a most undesirable throng of quasi-scientific humbugs, whose presence in their midst they resented with extreme frankness. There is a continual atmosphere of table-turning, mesmerism and magnetic flames in the tales extant about him, and though the narrators are tender about his memory, they have perforce to take up the attitude of counsel for the defence.
As a chemist, he undoubtedly came first in Scotland. He invented processes for the more perfect preparation of hydrochloric acid, muriate of morphia and oxyde of silver, besides making important observations on many other chemicals. He had an accurate command of practical chemistry, a power of condensation and clear expression, and a just perception of the value of discoveries, which made his writings unsurpassed for the use of students.
In 1844 Dr William Gregory realised the dream of his youth. After a sharp contest with Dr Lyon Playfair, he was appointed to succeed Professor Hope in his chair in the University of Edinburgh. ‘The chair was given to him,’ says Sir Alexander Grant, ‘under a new title, for the Town Council now judiciously omitted “Medicine” from its province, and elected Dr Gregory to be Professor of Chemistry.’
His health was much impaired, so much so, that people even went the length of saying that he was physically unfit for his new position, and it is at any rate true that his finest teaching was given to his students in Aberdeen. He was an able teacher, if at times erratic and absent-minded. His class was always kept wide awake, for with what alarms would not the professor bring back the straying imaginations of his audience! ‘Gentlemen,’ he would say, while with his long awkward fingers he lifted up the tube of some chemical before them, ‘If this were to fall, not one of you could reach the door alive;’ and then, considering the matter over, he would place the tube carelessly upon the edge of a plate, while the students near the doorway filtered through it, and the others, hat in hand, awaited the longed-for close of the lecture, feeling a fresh tremor with every approach of Gregory’s loose fingers to the fatal vial.