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TRANSACTIONS

OF THE EDINBURGH GEOLOGICAL SOCIETY.

SESSION 1897-98.

XLVI.—Dr Heddle and Ms Geological Work. By J. G. GOOD- CHILD, H.M. Geol. Survey, F.G.S., F.Z.S., Curator of the Collections of Scottish Geology and Mineralogy in the Edinburgh Museum of Science and Art. (Plate XX.)

(Read 16th December 1897.)

MATTHEW FORSTER HEDDLE was the younger son of Robert Heddle of Melsetter, Hoy, Orkney, where he was bom in 1828. His ancestors on both sides were of Scandinavian descent: it was therefore to be expected that some of the most prominent characteristics of the Norsemen should manifest themselves in his person sooner or later in life. It is to the antecedents of his forefathers, quite as much as to the nature of the surroundings amongst which he passed his earlier days, that we may attribute many of the characteristics which dis­ tinguished him in later life. From his boyhood he had been accustomed to wander amongst the dangerous precipices and lofty sea-cliffs of his native islands, of which it has been said that " there no man dies, for each one breaks his neck "; and he had, further, been early accustomed to trust himself alone in a small boat, in which he often traversed the wild seas of the Orkneys, or found his way from place to place along the dangerous coast-lines of those parts. Surroundings like these could not fail to leave a strong impress upon the character of any thoughtful and reflective youth; and those who knew Heddle in after-life had no difficulty in tracing the development of many of his characteristics to the influence of these sur­ roundings. It was to these early associations that he owed much of his very strong self-reliance; his readiness, when need VOL VII. PART IV. Y Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

EDINBURGH GEOLOGICAL SOCIETY. be, to face danger ; his fondness for things mysterious, vast, and impressive; and, lastly, the development of a powerful bodily frame and a strong constitution. From Orkney he went to school at the Edinburgh Academy. There he seems early to have distinguished himself by his readi­ ness to do battle on behalf of his weaker school-fellows. One or two stories told about him while there show him to have been possessed of considerable self-control, fortitude, and pluck. Some other stories connected with his life at the Academy are told in the well-known " Chronicles of the Canning Club," to which those interested in further details are referred. After leaving the Academy, Heddle went to Merchiston Castle, where we have records of him in 1842, '43, and '44. While there he stayed with the genial author of " Eab and his Friends," to whose influence Heddle was wont to attribute his tastes for natural science, and much else that was good in the later years of his life. - At Merchiston he helped to found a school Natural History Society, whose members energetically worked at the zoology and botany of the neighbourhood. Amongst those who were fellow-members with Heddle were Lauder Lindsay of Perth, Wyville Thomson, Lawson of Dal- housie College, Canada, Howden of Montrose, and others hardly less well known. It was at this stage of his career that he seems to have begun to develop that propensity for collecting which became his most dominant characteristic in after-life. He began, it is said, by collecting shells; and in the end he acquired, by this means, no inconsiderable knowledge of con- chology. He also got together the materials for a good herbarium. It was an incident connected with this latter which determined in what direction his collecting instincts should lead him in after-life. It is said that he had one day lent this herbarium to a friend, who, by an unfortunate acci­ dent while out driving, dropped the herbarium while he was crossing a stream, whereby the results of several years' work were utterly ruined. Heddle made up his mind, after this un­ toward accident, to collect no more things which could be so easily destroyed, and then straightway began to collect stones in their stead. The commencement of his geognostical work may be said to have dated from the period when that resolve was made. About this time he entered as a medical student at the University of Edinburgh, and underwent that course of training which has always constituted one of the very best possible foundations for scientific work of almost any kind. At the conclusion of his medical course, he went to Germany to study chemistry and mineralogy, going first to Clausthal and then to Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

Trans. Eclinb. Geol. Soc, Vol. VII., PI. XX. Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

DR HBDDLE AND HIS GEOLOGICAL WORK. 319

Freiburg. Eegarding Heddle in after-life as a geognoser, one cannot fail to perceive how the influence of the particular kind of teaching imparted to him at these seats of learning pervades much of what he thought and wrote. He returned to Edin­ burgh, and graduated as M.D. in 1851, taking as his graduation thesis " The Ores of the Metals." Soon after taking his medical degree, he commenced practice in Edinburgh, somewhere in the neighbourhood of the Grass- market. His reminiscences of this part of his life do not appear to have been altogether pleasant, and who that knows the neighbourhood and the people can wonder at that? The dismal and squalid nature of his surroundings, the low in­ tellectual grade of the people amongst whom his lot, for the time being, was cast; the absence of any prospect of obtaining more than the very smallest remuneration for the hard work he had to undergo, all seemed to combine to make him look forward to the time when he might escape from the duties of a profession which was evidently so uncongenial to his natural tastes and inclination. If I may judge from what I saw of Dr Heddle during a few years' fairly close acquaintance with him in the field, in the museum, in the study, and by his bed-side, I should say that Nature may have intended him for any one of many professions. He was pre-eminently adapted to become a first-rate actor; he would have made a clever lawyer; as a mechanician his talents showed themselves equally well; he was, as we all know, eminent as a mineralogist; he proved an excellent geognoser; but, assuredly, he did not possess that particular combination of special gifts and acquire­ ments which leads to success in the medical profession. So Dr Heddle eventually turned his attention from medicine, and for the remainder of his life devoted it to chemistry and geognosy. It is well for the scientific world that he did so, for the line of work that he then elected to adopt eventually led to his becoming one of the foremost mineralogists of his day. In 1856, soon after the date of this resolve, he chartered a boat and went to Faroe, where he succeeded in obtaining an extensive collection of zeolites from the Tertiary volcanic rocks. By means of the numerous duplicates so obtained, he was enabled to effect advantageous exchanges with other miner­ alogists, and by this means he formed the nucleus around which gathered his large general collection of minerals. For several years he acted as assistant to Professor Connell, who held the Chair of Chemistry at the University of St Andrews; and all through Connellys long illness and absence from the Lecture-Eoom there, Heddle filled his place. When Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

320 EDINBURGH GEOLOGICAL SOCIETY. the professorship at last became vacant, which was the case in 1862, Dr Heddle succeeded to the post. Dr Heddle filled the Chair of Chemistry at St Andrews for twenty years. He was very popular with the students for many reasons, but chiefly because he was an admirable lecturer, good at experiments and practical work, and possessing the gift—unfortunately so rare in those who hold such appoint­ ments—of inspiring his students with enthusiasm. In 1880 he was invited by a well-known financier to act as consulting-mineralogist in connection with some gold-mines in South Africa. After taking due precautions as regards possibilities in the future, in which part of the transactions Dr Heddle's turn for matters pertaining to law came into useful prominence, he vacated the Chair at St Andrews, and went to South Africa. But after making a full and proper inspection of the evidence on the ground, he felt himself unable to endorse some of the statements that had been made regarding the enterprise referred to. This step led to his return to Britain, and to some legal proceedings, in which he won his case. It may be mentioned that it was from the annuity which his foresight and legal acumen enabled him to secure from this undertaking, that he drew part of his income in the later years of his life. Mineralogy formed the chief of Dr Heddle's many pursuits. It was upon this, his favourite science, that nearly all his energy, his time, his thought, and also large sums of money were expended. It is a matter of common knowledge how, in the course of a long and active life, he acquired one of the finest general collections of minerals ever amassed by any one man, and also how, during the same time, he diligently 'explored nearly every mountain and glen, and almost every part of the coast of Scotland, in search of minerals. With Mr Patrick Dudgeon of Cargen, Mr Harvie-Brown of Dunipace, Mr James Currie, junr., and a few other chosen friends of similar tastes, he visited every locality for minerals which previous observers had recorded, and furthermore, himself added a very large number of new localities to the list of those previously known. These visits resulted in the acquisition of the celebrated "Heddle Collection of Scottish Minerals," the finest local collection in the world. Eventually circumstances led to Dr Heddle and some friends making an arrangement whereby his Collection of Scottish Minerals became the property of the nation. They are now located in the Gallery of Scottish Geology and Mineralogy in the Edinburgh Museum of Science and Art, where their arrangement was begun by Dr Heddle and is being completed by the writer of this notice. Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

DR HEDDLE AND HIS GEOLOGICAL WORK. 321

Dr Heddle wrote a large number of papers, chiefly on mineralogical subjects. The majority of one section of these appeared in the Mineralogical Magazine, under the general title of u The Geognosy and Mineralogy of Scotland." They include, as the title suggests, contributions to the Geology, as well as to the Mineralogy of the Doctor's native land. Another group of contributions was published in the Transactions of the Royal Society of Edinburgh, under the general name of " Chapters on the Mineralogy of Scotland." Those who will take the trouble to peruse the above-mentioned papers carefully, will find them full of terse statements, charged with suggestive matter, and embodying many original ideas. Not a few. of these appeared before the time when people in general were quite prepared to receive them, and they have consequently (as is usual in such cases) been somewhat extensively appropriated (generally without acknowledgment) by writers whose stock of original ideas has been more limited. For some of these researches Dr Heddle was awarded the Keith Medal of the Royal Society of Edinburgh in 1878. He contributed much to Greg and Lett- som's " British Mineralogy," the whole revision of which, before publication, was entrusted to him, and he wrote the article " Mineralogy " in the ninth edition of the Encyclopaedia Britan- nica. He was one of the founders of the Mineralogical Society of Great Britain and Ireland, and was one of their earliest presi­ dents. He was also at one time President of the Geological Society of Edinburgh, and while holding that office was instru­ mental in urging upon the Government of the day the import­ ance of instituting a Geological Survey of Scotland. He was also one of the oldest members of the Royal Physical Society, and took an interest in its welfare to the end of his life. Reference has already been made elsewhere to the fact that, for many years, Dr Heddle had been engaged on a compre­ hensive work on the " Mineralogy of Scotland," of which the greater part of the manuscript was completed by himself, and of which the illustrations, consisting chiefly of most beautiful and delicately-drawn figures of crystals, to the number of over six hundred, were also nearly all completed by the same skilful hand. This work is being edited and completed by Dr Heddle's old friend, Mr Alexander Thorns, and the writer of this notice, and will shortly be published in the form of two handsome royal octavo volumes, by Mr David Douglas. Regarding Dr Heddle's personal characteristics, one or two other points call for remark. Allusion has already been made to his strong dramatic instincts, to his histrionic talents, to his fondness for receiving mental impression of things grand, Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

322 EDINBURGH GEOLOGICAL SOCIETY. mysterious, and vast, as well as to his equally-marked fondness for impressing others with conceptions of the same kind. There must be very few of Dr Heddle's acquaintances who have not been aware of this characteristic of his. It was his power of mimicry, strong sense of the ludicrous, powerful dramatic instincts, and fondness for impressing those around him, which combined to make him one of the grandest story-tellers Scotland has ever known. Give him a few striking facts and a second or two to think over them, and he would found upon these a story which would command the attention and interest of all within hearing. Like Turner with the details of a landscape in his mind, the Doctor would think over and rearrange his facts, adding an artistic touch here, enlarging there, throwing sub­ ordinate facts into the background, and embellishing with minor details here and there throughout, until the whole was grouped into a striking and harmonious word-picture. There was a marvellous verisimilitude about some of his stories; so marvellous, in fact, that it occasionally happened that a few shallow-pated listeners accepted the whole story as perfectly true. Another characteristic of Dr Heddle's calls for remark. All of his acquaintances were fully aware of the fact that, for some few years past, he enjoyed bad health. But so powerful was his interest in his favourite pursuits, that the very mention of them would generally make him forget all his ailments, real and imagined, and he was then able to perform great walking feats, or to climb high mountains, to wield ponderous hammers, or to carry heavy bags of stones, each to an extent which few much younger men could well imitate. The large size of his hammers was very well known to his friends. Even his alpen­ stock was bigger than anyone else's, and one may truly say of it, as was said of the timber carried by one of the giants of old, that his staff" was like a weaver's beam." Like most other persons of strongly marked character, the Doctor evinced strong likes and dislikes, and therefore occa­ sionally made enemies. But his dislikes to the persons in question were usually founded upbn their having violated some principle, and not upon some motive affecting himself. I cannot recall a single instance of the contrary. In the case of a small number of persons of whose public conduct the Doctor had more or less reason to disapprove, the very mention of their names, even when he was in a state of extreme bodily and mental prostation, acted upon him like the sound of a trumpet- call to an old warhorse, and then those around him had the greatest difficulty in bringing him back to a state of quiet. For myself, who had much to do with Dr Heddle, I may Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

DR HEDDLE AND HIS GEOLOGICAL WORK. 323 say that, taking him all in all, I looked up to him much as Boswell looked up to Johnson. Like his prototype, he did much original work of good quality, and in the face of many difficulties ; like Dr Johnson he never sought honours (so none were conferred on him); like Dr Johnson he never appropriated other men's ideas; and, like Dr Johnson also, he was much given to doing kindly acts, in a quiet way, towards his fellow- men, and looking for no reward. The memory of one of whom we can truly say these things must surely long remain fresh in the minds of men of science.

To the scientific world in general, Dr Heddle was, of course, best known in connection with mineralogy. But no one who has attentively considered his various writings on that branch of science, can fail to perceive that his contributions to geology, especially in his papers on the Geognosy of Scotland, were hardly of less importance than his mineralogical work. In Dr Heddle's student days geology, in the modern sense of the word, may be said hardly to have come into existence; and those who had begun to pursue that branch of science had at first to feel their way very much in the dark. Most of the earlier work on the continent and in Scotland had to do chiefly with the materials of the earth's surface, and was very little concerned with any deductions that might be drawn from the study of those materials regarding either their relations to the history of the earth in the past, or to its architectural features of the earth at present. Geognosy, indeed, may be justly re­ garded as a sister science to Mineralogy, and as the parent of the modern sciences of Chemical Geology and Petrography. It is largely owing to the researches of the pioneers in this branch of geology that much of our present knowledge is due. Dr Heddle may be said to have had two principal objects in going into the field: firstly, to collect great quantities of the largest and finest specimens of Scottish minerals with his own hands; and secondly, to gratify his fondness for things vast, grand, and impressive, and for doing what other men had attempted to do and had failed. These motives led Dr Heddle to explore almost every known Scottish locality for minerals, and, in doing so, often to climb where it was dangerous, or to land where few else would venture, or to risk having to pass the night on moors remote from any human habitation. This, too, at a time when there were no Ordnance maps in existence, and few others upon which very much reliance could be placed. We are apt to forget about these matters in these days of easy travelling, Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

324 EDINBURGH GEOLOGICAL SOCIETY. when first-rate maps are to be had, and housing accommodation can always be counted upon. Thus it came about that Dr Heddle, while regarding nearly all geological questions from the standpoint of the chemist, yet did a large amount of field-work. If any proof were required of this, one need only refer to the geological maps of Orkney, Shetland, and Sutherland in his Geognosy of Scotland. In addition to these important published contributions to the Geology of Scotland, Dr Heddle had for many years been engaged upon a geological map of Aberdeen, Elgin, Nairn and Banff, and some of the adjoining parts of Inverness, which he never completed. When it is considered how little was actually known regarding the geological structure of large parts of these areas, it must be matter for wonder how any one man, working single-handed, bearing his own expenses, and hampered by having to work with unreliable maps, and by the innumerable difficulties presented by both the nature of the ground and the complicated structures of the rocks, could accomplish so much in a single lifetime. If, of this part of Dr Heddle's work, it has happened, in a few cases, that fuller investigations had led to different interpretations of the facts, all must admit that, like MacCulloch, Nicol, Hay Cunningham, and others, he helped very materially to lay the foundations of our present knowledge of the Geology of Scotland; and, like other early workers, he often made statements and recorded facts which were questioned for a time, then accepted, and, ultimately, credited to later writers. Amongst what we may term Dr Heddle's minor contributions to geology, special attention may be called to his observations on the nature of pegmatites. Dr Heddle devoted very con­ siderable attention to these interesting forms of crystalline rock, and much that he wrote about them, being based entirely upon his extensive and close observation in the field, is both suggestive and valuable, and contained ideas which were very far in advance of the general knowledge of the time at which he wrote; and it is perhaps hardly going beyond the mark, to state that Dr Heddle's views regarding pegmatites are, even yet, ahead of any others. Upon another point of geological importance he was the first to pronounce with decision. Normal granite consists of a holocrystalline compound, with granitic structure, of quartz and potash felspar, with, or without, other constituents. Dr Heddle pointed out, in his " Chapters on the Mineralogy of Scotland," when referring especially to the grey granite of Aberdeenshire, that the dominant felspar in this granite was not Orthoclase, nor a potash felspar of any kind, but the soda-lime felspar Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

DR HEDDLE AND HIS GEOLOGICAL WORK. 325

Oligoclase. Subsequent investigation has abundantly proved the truth of this statement, and, furthermore, has shown that it is true also of the great majority of Scottish granites. He was also the first to point out the relative abundance of Microcline, especially in Scottish pegmatites, in which the felspars are usually Oligoclase together with this form of potash felspar. A further generalisation of Dr Heddle's with regard to the felspars, was the comparative rarity of Albite in Scottish rocks, and the abundance and wide diffusion amongst the sub- basic and basic erupture rocks of Labradorite. All these generalisation are geological points of considerable importance. Then, with regard to the micas, he has shown that of the dark micas the commonest in both the erupture and the gneissose rocks of Scotland is Haughtonite, while Biotite proper is almost confined to thermo-metamorphosed limestones. Another of Dr Heddle's generalisations, which has important geological bearings, relates to the specific heat of colloid sub­ stances as compared with that which the same substances have when in the crystalline condition. Applying the principle to limestones, he pointed out that in the change from the amorphous, or original form, to the crystalline form which they subsequently assume under particular conditions, a quantity of heat equivalent to the difference between the specific heat in the amorphous and that in the crystalline condition has been liberated. He stated his belief that the heat thus disengaged was sufficient to produce very important modifications upon the surrounding rocks. In the Gallery of Scottish Geology .and Mineralogy in the Edinburgh Museum of Science and Art, he has displayed specimens of his own collecting which he believed bore out this principle very fully. Another point related to the last, and also of importance in connection with rocks of metamorphic origin, upon which he often spoke (but the present writer is not aware that he ever published it), relates to the fact that, when rocks are affected by dynamic action, part of the energy of motion, as is well known, is converted into the energy of heat; but that if the dynamic cause operates a second time, after the heat has been so disengaged, the rock simply breaks up, with little or no dis­ engagement of heat. He believed that one of the chief effects •of the dynamic action was to develop a crystalline structure in rocks that had been previously amorphous, and that the heat liberated was chiefly that due to the difference in the specific heat in the two states. [Dr Heddle's conclusion might be pushed further and applied to explain the development of .granulitic structure in dynamically metamorphosed rocks, which structure would thus appear to be due to the effects Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

326 EDINBURGH GEOLOGICAL SOCIETY. of a second movement after the crystalline stage had been developed, provided that these rocks had not in the meantime been exposed to heat from outside sources, or, in other words, annealed.—J. G. G.] In another of Dr Heddle's unpublished statements, he ex­ pounded some of the laws that govern the rounding of grains of sand.1 In this some important and valuable suggestions were made, some of which the present writer has adopted (with acknowledgment) and extended, in a paper read before the Edinburgh Geological Society on "Desert Conditions in Britain.,, Along another line of enquiry Dr Heddle had worked for many years. This was in connection with the origin and structure of agates—a. subject which he may be said to have made almost peculiarly his own. Many of the conclusions possess an interest chiefly for the physicist; but amongst those which are of interest to the geologist may be mentioned his remarks upon the formation of the onyx bands in agates. These, he has shown, were deposited within the agate in an absolutely horizontal position, and at an early stage in the history of the rocks in which they occur, and almost invariably before any disturbance affected those rocks. [Any inclination these onyx bands may now possess is therefore a measure of dip of the rocks, and is, perhaps, the only means we possess of measuring the angle through which a lava has been moved subsequently to its consolidation.—J. G. G.] X)r Heddle specially prided himself upon his contributions to the history of dolomitisation of limestones. He was one of the first to show that in the conversion of a normal limestone into dolomite a certain easily-estimated diminution of volume took place, which, as he and others have pointed out, has led to the formation of a carious structure in the rock, and to the development of the well-known geodes that characterise lime­ stones which have been converted into dolomite. Lastly, reference may be made to the germs of another principle of geological importance of which the present writer has heard Dr Heddle speak. The Swiss geologists, from the early days of Agassiz downwards, have recognised that the sun's rays falling upon ice or snow do not raise the temperature of the ice or the snow so much as they do that of foreign bodies that may happen to lie below the surface! Professor Tyndall has also made reference to the same principle. Dr Heddle used to say that it was this cause which made dirt and stone& on the surface of the ground beneath snow tend to melt their way upward towards the surface. [The present writer has 1 Lecture on " Sand " given before the Edinburgh Field Naturalists. Downloaded from http://trned.lyellcollection.org/ at Purdue University Library on June 25, 2015

DR HEDDLE AND HIS GEOLOGICAL WORK. 327 extended this principle, and applied it to explain the uplift of stones within the Great Ice sheet, and therefore to the elevation of boulders to positions higher than that of their sources.] The limits of this notice forbid fuller reference to Dr Heddle's contributions to geology; but enough has been pre­ sented here to justify the statement made at the head of this section, and to which the present writer is disposed firmly to hold, that Dr Heddle's geological work is nearly equal in importance to his contributions to mineralogy.