The Right Honourable Sir Henry Enfield Roscoe P.C., D.C.L., F.R.S. / A Biographical Sketch

by T. E. Thorpe

He also published two text-books on “Inorganic Chemistry,” one for beginners, in conjunction with Dr. Lunt; and a larger one for advanced students, in association with Dr. Harden, each of which has reached a second edition.

A far more ambitious undertaking was the preparation and publication of the large “Treatise on Chemistry,” in the writing of which he had the invaluable co-operation of his colleague Schorlemmer. The first volume appeared in 1877. It is so well known that no description of it is necessary. It is an eminently readable work, admirably printed and beautifully illustrated. Indeed, in style and appearance it is hardly approached by anything of the kind in the language. It was translated into German by Schorlemmer, and published by Vieweg & Son, and has now largely replaced the time-honoured Graham-Otto as a text-book in German colleges and technical schools. Unfortunately, owing to Schorlemmer’s death in 1892, the organic section in the English edition was never finished. It has, however, been completed in the German edition under the direction of the late Professor Brühl of Heidelberg—a circumstance which would seem to throw some light on the comparative position of organic chemistry in this country and in Germany. It ought, however, to be stated that if the whole of the organic section were compiled with the same attention to historical detail, and the same fullness of information that characterizes the inorganic portion, the work would become practically unsaleable on account of its size. At the time the treatise was planned the extraordinary expansion of organic chemistry which has occurred during the past forty years could hardly have been anticipated. It may be, as old Thomas Fuller wrote, that “learning hath gained most by those books by which the printers have lost.” But philanthropy is not the first business of publishers.

The inorganic section of the English work has passed through several editions, and was thoroughly revised and largely re-written from time to time with the help of numerous collaborators. The fifth edition on “The Metals and their Compounds” made its appearance in the autumn of 1913—and is a goodly volume of nearly 1,500 pages. Roscoe, then in his eightieth year, worked hard at the revision and read the proofs with all the care and diligence he expended on the original work.

Some time prior to 1895 he was induced by his friend, the late Sir Wemyss Reid, to undertake the editorship of the Century Series of Biographies of Scientific Men, projected by Cassell & Co. To this he contributed a popular account of the life and work of Dalton under the title of “John Dalton and the Rise of Modern Chemistry”—a little work which he wrote with much zest and a thorough appreciation of the fine character of the grand old Cumbrian Quaker.

Mention has already been made of the “New View of Dalton’s Atomic Theory,” which Roscoe published in collaboration with Dr. Harden. This book is of considerable interest and value in regard to the genesis of a conception which marks a turning-point in the history of chemistry. From a careful study of Dalton’s manuscripts and note-books which had been discovered in the rooms of the Literary and Philosophical Society of Manchester, the authors were led to conclusions concerning the origin of the atomic theory of chemistry which differ fundamentally from those which had been generally accepted. It had hitherto been supposed that it was the experimental discovery of the law of combination in multiple proportions which, in his search for an explanation of this fact, led Dalton to the idea that chemical combination consists in the approximation of atoms of definite and characteristic weight, the theory of atoms being adopted to explain the facts discovered by chemical analysis. In reality the exact opposite was the case. It was the theory of the existence of atoms of different weights that led Dalton to the discovery of the facts of combination in multiple proportions.

The late Dr. Debus, some two years previously in a pamphlet published at Cassell, had reached a similar conclusion from a study of Dalton’s published works, but by a different line of argument. As a matter of priority there is no doubt that to Debus belongs the credit of first pointing out that the commonly accepted view of the genesis of Dalton’s atomic theory is erroneous, but it is no less true that the method of reasoning by which he came to that conclusion cannot be substantiated even if it is not actually disproved by the evidence from Dalton’s note-books. Of course the idea of atoms, that is, of small indivisible particles, did not, as is popularly supposed, originate with Dalton: it is older than Science itself. How and where it first arose cannot be exactly stated. Dr. Debus attributes it to Moschus, a Phœnician philosopher living at Sidon about 1100 B.C. It was resuscitated by Gassendi in the middle of the seventeenth century, and applied by Boyle, who speaks of it as the Phœnician philosophy, to the explanation of chemical phenomena. Newton made use of it to explain Boyle’s law and the “spring of air.” Dalton almost certainly derived it from Newton, with whose corpuscular notions he was quite familiar, and employed it to explain the phenomena of diffusion and absorption. He was therefore quite ready to extend it to all gaseous phenomena, and indeed to chemical phenomena in general, to the extent that it seemed applicable.

It has been held that Dalton anticipated Avogadro in assuming that all gases contain equal numbers of “atoms” (molecules). Dr. Debus adopts this view, and assumes that Dalton in 1801 made use of it to explain the phenomena of the diffusion of gases, and that this idea, along with his early experiments on nitric oxide and oxygen, led to his atomic theory. Roscoe and Harden, on the other hand, held that Dalton never definitely held the view that equal volumes of gases contain an equal number of atoms (molecules), nor had such a conception any bearing upon his explanation of the facts of diffusion. Dissatisfied with the theory which he did hold (viz. the repulsion exerted by an atom on all others of its kind, but not on atoms of a different kind), he was led to consider the behaviour of atoms of unequal size, and finding an agreement with the observed facts, he then sought for means of determining whether or not the atoms were actually of unequal size, and so was led to the further developments of the theory. The weight of the evidence goes to show that Dalton arrived at his theory in the latter half of 1803, and that assumption on which it turned was “that no two species [of pure elastic fluids] agree in the size of their particles.” There is no clear indication that Dalton ever imagined that the simple gases were diatomic in structure, which, of course, is the main point in Avogadro’s hypothesis. It seems necessary to set out this matter in some detail as misapprehension appears to exist, especially in Germany, as to the merits of the controversy which arose after the appearance of Roscoe and Harden’s work.

Some years after he had reached the allotted span, Roscoe was induced to think of putting his reminiscences on paper. It was at no time easy to get him to talk about himself, and the effort of recalling his recollections with a view to printing them was irksome to him. The autobiography consequently made no very rapid progress; it ultimately got into something like a tangle, and was more than once on the point of being committed to the flames. However, during a particularly stormy winter at the seaside, when he was confined to the house, a sustained effort on the part of a determined coadjutor got it into shape, and under the title of “The Life and Experiences of Sir Henry Enfield Roscoe, D.C.L., LL.D., F.R.S. Written by Himself,” it was published by Macmillans in the spring of 1906. The book was well received. It was recognized as possessing at least two of the main essentials of a successful autobiography—something worth writing about and the faculty of narration. It is written with sincerity and directness, and with, as one critic said, “a charming simplicity of style and thought, illumined throughout by a soft glow of kindly humour” eminently characteristic of its author, and is of interest as a record of a singularly full and varied career. The gospel of work never had a more strenuous disciple. It has historical value also as the story of the educational changes, particularly in science, which he helped to secure or lived to witness. It reflects many of his noteworthy features: his strong common sense; his straightforwardness and honesty of purpose; his liberality and invincible optimism; his geniality and sense of humour. His enjoyment of a good story makes him tell it even if he is the victim of it. The whole is a pleasing picture of a uniformly calm, contented, and successful life—of the life of one who was what the Romans called “a man of good fortune,” that is, of one whose prosperity was not the result of chance or accident, but of wisdom and the capacity to bring its aims and efforts to a successful ending.