William Gregory was the last of this great academic family to hold a chair in a Scottish University.

He was the fourth son of Professor James Gregory, and having been brought up among the traditions of medicine, he turned to the study of it instinctively, though the necessity laid upon him was by no means the same as that which had made his forefathers physicians in spite of themselves. He had not gone far in his medical course when he decided to be a chemist rather than a doctor. The magic of Professor Hope’s experiments made at least one convert and as he sat in the class-room observing the strange effects of chemicals, he made up his mind that if it were possible he would some day take the teacher’s place. With rude implements he would spend hours at home repeating the processes which he had watched in the class, his mind all alive to the interest of his subject, and his poor body much neglected. These happy hours in his laboratory were dearly paid for by the delicacy, which began to show itself about this time. The noxious fumes of the chemicals acted as a slow poison, and from this stage of his life he had to struggle with ill health, all his occupations being interrupted at times by unconquerable pain.

He graduated M.D. in 1828, and then went abroad to study chemistry in the famous schools of the continent. At Giessen, the most important of these, he had the good fortune to attract the attention of the great teacher, whose work had made the university famous, and from this time forward, Liebig was the friend and correspondent of William Gregory.

During the years when Gregory was completing his studies abroad, and teaching successively in Edinburgh, Glasgow, and Dublin, King’s College, Aberdeen, was going through considerable difficulties in connection with the post of mediciner. In the days of John Gregory’s tenure of that office, he had as we already know, made efforts to improve the medical curriculum there, but without success. A step in advance was made in 1801, when it was determined that a candidate for the degree of M.D. must ‘oblidge himself that he is not, nor will be concerned in the sale of quack medicines of any description!’ and a further step was taken in 1817 by the authorities insisting on a satisfactory account of the ‘classical, literary and scientifical education of the candidate.’

Between 1824 and 1826, an attempt was made by the Chancellor and Senatus to insist that the mediciner should teach medicine, but Dr Bannerman, who then held that office, would only consent to consider the matter for a year, and after that time he let it rest. In 1836, he was advised that if he would neither teach nor appoint a substitute, a lecturer would be chosen, and paid out of his salary. This threat, however, was never carried out, and he died in 1838, and it was to this post of mediciner, made vacant by his death, that William Gregory was appointed on February 19th, 1839.

Dr William Pulteney Alison, to whom the electors of King’s College applied for suggestions as to a suitable candidate, had curiously enough never mentioned the name of his cousin, and it was only owing to the intervention of Thomas Clark who held the Chair of Chemistry in Marischal College that Gregory came to apply. After giving him minute instructions as to the form which his application must take, he added, ‘Don’t mention me no more than the Devil.’ The name of this friend was therefore kept out of sight, and Gregory was in due course appointed to the vacant professorship. It was with great joy that his advent was announced to the professors of King’s College. Their difficulties in improving the medical course, when the very mediciner would not teach a class, had been insuperable, but now they felt a man of influence was coming amongst them, who would be the means of promoting the interests of their university, and who would give the benefit of a hereditary power of teaching to the students, whom they felt sure his great name would attract to their midst.

While in Aberdeen William Gregory became intensely interested in the welfare of King’s College, and busied himself in trying to secure revenue from the government to found new chairs, but in this he was unsuccessful.

He taught Materia Medica in a house fitted up for a Medical School in Kingsland Place, and he had a good class, but from the witticisms of the students as to the effect of their professor’s preparation of muriate of morphia it is evident that William Gregory’s physical weakness was growing upon him, and that it was only with the most strenuous effort that he could get to his class at ten o’clock.

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.

Good as his teaching was, the books which he wrote while in Edinburgh were his most valuable contribution to the Science of Chemistry. In the preface to the Outlines of Chemistry, which was published in 1845, he sketched the divisions which he intended to make in his subject for the fuller elucidation of the facts, and, had his health permitted him to carry out his plan, ‘the instruction from his class would probably have been more complete than from any other scientific chair in Europe.’ At the request of Liebig, he translated several of his more important books into English, and in the preface to the Familiar Letters on Chemistry, Liebig writes, ‘From his intimate familiarity with chemical science, and especially with the physiological subjects here treated, I am confident that the task could not have been entrusted to better hands than those of my friend Dr Gregory.’ Their friendship lasted throughout life, and only a few days before Professor Gregory’s death, he was propped up in his bed to write a pamphlet supporting some new theories of Liebig, which the German had just communicated to him.

Gregory’s appearance was most noticeable. He was of great proportions, obese, slouching and loosely hung together. In later years his body was a great burden to him, but the mind kept the mastery.

He was, like his father, a keen student of language, and would wile away many of the weary hours of forced inaction by the study of foreign tongues. French and German were to him as familiar as English. With a microscope, too, he did beautiful work, and was in his day, the greatest authority on the Diatomaceae. The slides which he made of these microscopic water-plants with their sculptured valves, were another resource of his declining years. He presented valuable memoirs on this subject to the Royal Society of Edinburgh, of which he was a member.

Professor William Gregory died in Edinburgh in April 1858, and was honoured with a public funeral.

He was succeeded in the university by Dr Lyon Playfair (afterwards Lord Playfair) who had contested the chair unsuccessfully at the time of Gregory’s appointment.

William Gregory was survived by an only son, who was called after his father’s far-famed friend, James Liebig Gregory.

Duncan Farquharson Gregory was considerably younger than his brother the Professor of Chemistry, and was not at all like him in personal appearance. His face was a beautiful one, fine, pale, bearing on it already in this life some of the light and joyousness that often mark out for especial love those who are to pass quickly from this earth. His hair, which was thick and curling, fell more about his brow than is usual, and his eyes like dark lamps illuminated his features.

When he was hardly more than a baby, his father used fondly to predict distinction for him. ‘He had pleasure in conversing with him as with an equal on subjects of History and Geography,’ so Mr Ellis wrote, and this when the boy was not more than six, for his father died before he had left the nursery. He was a great inventor of games for himself, and made an orrery with his busy little hands, on which he would send the planets spinning round in their orbits.

Till he was nine years old he was taught entirely by his mother, who was quite as attractive to her children as she had ever been in society, and for whom Duncan had always a peculiar reverence and affection. He passed out of her hands into the care of a tutor, and then was sent to the Edinburgh Academy. From school he went abroad to Geneva, where his mother and sisters were spending a winter, and on his return he attended classes at the University of Edinburgh. In mathematics he made astonishing strides, under Professor Wallace, and those who saw the master and pupil together in Cambridge in after days, said that the old man’s pride in his pupil’s success never diminished.

In 1833 Mr Gregory’s name was entered at Trinity College, Cambridge, and shortly afterwards he went to reside there. He took with him a most unusual amount of knowledge on almost all scientific subjects, in fact many men said that it was the diffuseness of his learning that prevented him from taking the first place in the mathematical honours in that university; for when the tripos came he was only fifth wrangler.

A few months after his arrival in Cambridge he agreed to act as assistant to the Professor of Chemistry, and he was one of the founders of the Chemical Society, and occasionally gave very charming lectures in their rooms. His other pursuits were botany, natural philosophy, and astronomy, but his most serious study was of course mathematics.

After taking his degree of B.A. in 1837, he felt himself more at liberty to follow original speculation, and turned his attention to the general theory of the combination of symbols. His studies in this subject appeared from time to time in the Cambridge Mathematical Journal, of which Duncan Farquharson Gregory was editor, with only an interval of a few months, from its first appearance till shortly before his death.

Mr Gregory was in 1840 elected a Fellow of Trinity College, and he took his M.A. degree in the following year. In that year, too, he was appointed to fill the office of moderator in the Mathematical Tripos. This position, which is regarded as one of the most honourable of those to which the younger members of the university may aspire, was filled by him with great success.

His most considerable book (though possibly less well known than his lucid work on solid geometry), appeared about this time. It is entitled Collection of Examples of the Processes of the Differential and Integral Calculus, and was thoughtful and original. At first his plan had been to edit a second edition of a work with a similar title, which twenty-five years before had come from the pens of Herschel, Peacocke, and Babbage, but as he considered this, he discovered what immense strides had been made in the general aspect of mathematics. The mathematical theories of heat, light, electricity, and magnetism were all new, and they required a fresh treatment. Thus he undertook the book which brought him so much honour.

Gregory had an absolute passion for mathematics. ‘All these things seem to me,’ he said once, while turning over the pages of Fourier’s great work on heat, ‘to be a kind of mathematical paradise,’ and the enjoyment comes out all through his book.

He contested unsuccessfully with Professor Kelland the Chair of Mathematics in the University of Edinburgh, and in 1841 was offered the corresponding chair in Toronto, which, however, he declined; and it was well that he did so, for in the following year he had the first attack of the illness which was to end fatally for him. In the spring he left Cambridge never to return again.

Up to the last he had taken part in his college work, and in spite of severe suffering had gone through the irksome labour of examinations. Months of all but constant pain followed, brightened only by short intervals of ease. Whenever these occurred he turned to his old studies for refreshment, and only a little while before his death he began a paper on the analogy between differential equations and those in finite differences.

As the weeks passed, the watchful eyes of his sister could see the gradual failing of his strength, and at five o’clock on the morning of February 23rd, 1844, he passed away in his sleep. He died at Canaan Lodge.

His sister, Miss Georgina Gregory, made a collection of the poems written by her brothers. Some of Mr Duncan Gregory’s verses would have made delightful children’s poetry. One time when they had gone to the English lakes together for change of air, they, as is not an entirely unknown experience in that part of the world, had to spend most of their time in the inn, and as a last resource fell to writing doggerel.

He was a delightful brother and a delightful friend. What he might have done as a mathematician had he but lived it is impossible to tell. As it is, a writer who has discussed the hereditary qualities of the family, speaks of the mathematical genius, which had lain dormant since the time of James Gregorie as ‘blazing forth’ again in Duncan Farquharson Gregory, and if this writer passes over such talents as those of David Gregory, the Savilian Professor at Oxford, he must have held the Fellow of Trinity in great honour. Another authority on the family, said that if Duncan Gregory were alive, which he might quite well be as far as dates are concerned, he would probably have been the most famous pure mathematician of the day. And a still greater testimony is that of Lord Kelvin, given at the Bristol meeting of the British Association in 1898, where in a paper on ‘Graphic Representations of the two Simplest Cases of a Single Wave,’ he referred to Gregory’s work on this subject. ‘Gregory,’ he said, ‘died too soon,’ and as he turned from the black-board on which he had been drawing some diagrams, he added, ‘we cannot tell what we might have known if Gregory had lived.’ His talent was appreciated when he lived, but the qualities to which his friends reverted with most tenderness were his unenvious appreciation of other men’s work, his sweetness and joyfulness, and the patience with which he bore his last long illness.