BLACK, Joseph.

Dissertatio medica inauguralis, de humore acido a cibis orto, et magnesia alba... [Bound as the third item in a sammelband with eight other medical dissertations (listed below)].

Edinburgh: G. Hamilton & J. Balfour, 1754.

First edition of one of the greatest rarities in the history of science, the discovery of carbon dioxide and the foundation work of quantitative chemical analysis. “There is perhaps no other instance of a graduation thesis so weighted with significant novelty as Black’s ‘De humore acido a cibis orto, et magnesia alba’ presented to the Faculty, 11 June, 1754” (William Osler in DNB). It “was soon recognised for what it is: a brilliant model, perhaps the first successful model, of quantitative chemical investigation, as well as a classic exemplar of experimental science worthy of comparison with Newton’s Opticks … The Dissertatio in its original form is virtually unprocurable” (Guerlac, p. 124). Black’s biographer Sir William Ramsay, who was awarded the 1904 Nobel Prize in chemistry “in recognition of his services in the discovery of the inert gaseous elements in air,” wrote of “Black’s celebrated thesis, which gained for him not merely the degree of Doctor of Medicine, but also brought his name before every ‘philosopher’ in Europe and America as that of a man who had made a discovery of more fundamental influence on the progress of Chemistry than any which had previously been described” (Ramsay, p. 20). “In the late spring of 1754, the famous Scottish chemist and physician Joseph Black (1728-99) put the finishing touches on his thesis for the doctorate of medicine at the University of Edinburgh. Entitled Dissertatio medica inauguralis, de humore acido a cibis orto, et magnesia alba, … it has received unstinted praise as one of the great classics in the history of science … [Black] studied and carefully distinguished the chemical behaviour of the common alkalis (carbonates) and of the two alkaline earths, lime and magnesia. He showed that the changes produced in these substances by roasting and calcining the mother substances (limestone, chalk and magnesia alba) were associated with the loss of an elastic, aeriform constituent, a ‘fixed air’ [carbon dioxide], and need not be explained by assuming that some hypothetical ‘principle’ was added during intense heating. Most important of all, Black proved by careful gravimetrical experiments that this elastic fluid was a precise quantitative constituent of these chemical compounds. As is well known, Black’s results led directly to the classic studies on gases carried out by Henry Cavendish, Joseph Priestley, and Black’s own pupil, Daniel Rutherford” (Guerlac, p. 125). An expanded English translation was published by the Edinburgh Philosophical Society in 1756, and the original thesis was reprinted in 1785 in William Smellie’sThesaurus medicus (Tom. II, pp. 271-304). ESTC lists 11 copies of the Dissertatio worldwide (7 in the UK, 3 in North America, and one in the Netherlands). We have been unable to trace any other copy having appeared in commerce.

Joseph Black was born in Bordeaux where his father, who was born in Belfast but was ultimately of Scottish descent, had a wine business. Joseph was sent to school in Belfast in 1740, and around 1745 entered Glasgow University, where he studied languages and natural philosophy, and later, about 1748, anatomy and medicine under William Cullen. After working for three years in Cullen’s laboratory, in 1752 Black left Glasgow for the more prestigious University of Edinburgh, where he attended the lectures of the physiologist Robert Whytt, and of Charles Alston, a botanist and chemist who lectured on materia medica. “In 1754 Black received the M.D. with his now historic dissertation De humore acido a cibis orto et magnesia alba” (DSB). Black succeeded Cullen as professor of anatomy and lecturer in chemistry in Glasgow in 1756, but exchanged the chair of anatomy with the professor of medicine. He succeeded Cullen as professor of chemistry in Edinburgh on 1 November 1766, and occupied that position, at the same time practising medicine, until his death in 1799.

“Black’s investigation of alkaline substances had a medical origin. The presumed efficacy of limewater in dissolving urinary calculi (‘the stone’) was supported by the researches of two Edinburgh professors, Robert Whytt and Charles Alston. It interested Cullen as well, and Black came to Edinburgh as a medical student with the intention of exploring the subject for his doctoral dissertation.

“But at this moment Whytt and Alston were at loggerheads: they disagreed as to the best source, whether cockleshells or limestone, for preparing the quicklime. And they differed as to what occurs when mild limestone is burned to produce quicklime. Whytt accepted the common view that lime becomes caustic by absorbing a fiery matter during calcination, and thought he had proved it by showing that quicklime newly taken from the fire was the most powerful dissolvent of the stone. Alston, in an important experiment on the solubility of quicklime, showed that this was not the case, and that the causticity must be the property of the lime itself. Both men were aware that on exposure to the air quicklime gradually becomes mild, and that a crust appears on the surface of limewater. For Whytt, this resulted from the escape of fiery matter; but Alston, noting that the crust was heavier than the lime in solution, hinted that foreign matter, perhaps the air or something contained in it, produced the crust. Yet he was more disposed to believe that the insoluble precipitate formed when the quicklime combined with impurities in the water. Black, although he had criticized Alston as a chemist, was soon to profit from his findings.

“Preoccupied at first with his medical studies, Black did not come to grips with his chosen problem until late in 1753. When he did so, he found it expedient to avoid any conflict between two of his professors; instead of investigating limewater, he would examine other absorbent earths to discover, if possible, a more powerful lithotriptic agent. He chose a white powder, magnesia alba, recently in vogue as a mild purgative. Its preparation and general properties had been described by the German chemist Friedrich Hoffmann; although it resembled the calcareous earths, magnesia alba was clearly distinguishable from them.

“Black prepared this substance (basic magnesium carbonate) by reacting Epsom salts (magnesium sulfate) with pearl ashes (potassium carbonate). He treated the purified product with various acids, noting that the salts produced differed from the corresponding ones formed with lime. The magnesia alba, he observed, effervesced strongly with the acids, much like chalk or limestone.

“Could a product similar to quicklime be formed by calcining magnesia alba? Would its solutions have the causticity and solvent power of limewater? Black’s effort to test this possibility was the turning point of his research. When he strongly heated magnesia alba, the product proved to have unexpected properties. To be sure, like quicklime, this magnesia usta [magnesium oxide] did not effervesce with acids. But since it was not sensibly caustic or readily soluble in water, it could hardly produce a substitute for limewater.

“The properties of this substance now commanded Black’s entire attention, notably the marked decrease in weight that resulted when magnesia alba changes into magnesia usta. What was lost? Using the balance more systematically than any chemist had done before him, he performed a series of quantitative experiments with all the accuracy he could command. Heating three ounces of magnesia alba in a retort, he determined that the whitish liquid that distilled over accounted for only a fraction of the weight lost. Tentatively he concluded that the major part must be due to expelled air. Whence came this air? Probably, he thought, from the pearl ashes used in making the magnesia alba; for Stephen Hales, he well knew, had shown long before that fixed alkali “certainly abounds in air.”^. If so, upon reconverting magnesia usta to the original powder, by combining it with fixed alkali, the original weight should be regained. This he proved to his satisfaction, recovering all but ten grains.

“Magnesia usta, he soon found, formed with acids the same salts as magnesia alba, although it dissolved without effervescence. Only the presence or absence of air distinguished the two substance: magnesia alba loses its air on combining with acids, whereas the magnesia usta had evidently lost its air through strong heating before combining with acids.

“Could the same process – the loss of combined air – also explain the transformation of lime into quicklime? Tentative experiments suggested something of the sort; but not until the work on magnesia was completed, late in 1753, did he examine this question. When he precipitated quicklime by adding common alkali, the white powder that settled out had all the properties of chalk, and it effervesced with acids. Early in 1754, Black wrote William Cullen that he had observed interesting things about the air produced when chalk was treated with acid: it had a pronounced but not disagreeable odor; it extinguished a candle placed nearby; and “a piece of burning paper, immersed in it, was put out as effectually as if it had been dipped in water.” This was an observation clearly worth pursuing. Nevertheless, he could no longer postpone the writing of his Latin dissertation and his preparation for his doctoral examination.

“The dissertation is in two parts: the first, dealing with gastric acidity, was clearly added to give medical respectability to the work; Black was never happy about it, and hoped it would pass ‘without much notice’” (DSB).

The second part of the dissertation includes a “terse monographic treatment, experiment by experiment, of magnesia and some of its compounds and properties, including of course the epoch-making Experiments XX-XXIV, which seemed to prove the role of a fixed air in the transformations that magnesia underwent. The first twenty-four experiments, all having to do with magnesia, were performed in the course of the year 1753, and were almost certainly carried out in the order in which they are presented in the published account. They must have been completed by January 1754, when Black’s letter to Cullen shows that he was observing the properties of fixed air produced from chalk. There is evidence that the last eight experiments were performed after 15 January of that year …

“The theory that he advanced seem to him ‘to lead into a set of consequences or conclusions inconsistent with common received opinions and facts commonly held to be incontrovertible, I could not help entertaining some doubts, which I resolved to try by experiments.’ The implications of this theory ‘drew after them a set of circumstances so contradicting to the common opinion, that I resolved to determine the truth of them by experiment before I published them to the world.’

“These consequences Black formulated in a set of five propositions which he proposed to test by experiment:

(1) Effervescence with an acid was formerly supposed to be an essential quality of every alkaline substance. But if, by Black’s theory, this results only from the loss of fixed air from a calcareous earth, then ‘if we only deprive the earth of its fixed air by burning it, it should unite with acids as well, and should saturate the same quantity as formerly, but without effervescence.’

(2) If quicklime is only calcareous earth deprived of its fixed air, then it should be possible to restore it to its original state, as he had done with magnesia usta, by giving it back its fixed air by the action of an alkali.

(3) If quicklime receives no subtle particles from the fire, but is a uniform earthy substance, then the whole of a sample of lime should dissolve if only sufficient water is added.

(4) If the causticity of an alkali arises entirely and the transfer of fixed air from the weak alkali to the lime (and does not depend on the addition of any particles of lime) then it should be possible to make calcareous earth caustic without the aid of fire.

(5) If the ‘only effect which fire has upon the calcareous earth is to deprive it of its fixed Air, it is evident that we can make a quicklime by any means that will separate [sic] the fixed air from the earth,’ as by the action of a caustic alkali.

“It is probable that before mid-January 1754 Black made one or two preliminary attempts to verify the truth of these propositions …

“We can easily understand the dilemma in which Black found himself in January 1754. With his sound chemical insight, he realised that his confirmatory experiments would have to be carried out quantitatively and with materials of the highest purity, or he would end up with the results as ambiguous as those of Whytt and Alston. This was sure to be laborious and hardly the sort of undertaking to embark upon when he must finish his long delayed thesis and prepare for his examinations before June of the year … At this point, probably in January 1754, we may well imagine Black undertaking somewhat ruefully and without enthusiasm the padding of his thesis … He prefaced the experiments already enumerated with a clumsy medical introduction entitled ‘On the Acid Humour Arising from Food,’ which he introduced rather apologetically at the beginning of the thesis” (Guerlac, pp. 436-438).

“Black had shown that a particular kind of air, different from common air, can be a quantitative constituent of ordinary substances and must enter, as Lavoisier put it later, into their ‘definition.’ But he was not destined to make the investigation of such elastic fluids his ‘future inquiry.’ This was to be mainly the work of his British disciples – Mac Bride, Cavendish, Priestley, and Rutherford – and he published nothing further on the subject [after the expanded English edition in 1756]” (DSB).

The other dissertations contained in the present volume are as follows (in binding order):

MONROE, Donald. De hydrope. Edinburgh: Hamilton, Balfour & Neill, 1753.

CAMPBELL, John. De aere quatenus morborum causa. Edinburgh: W. Sands, A. Murray & J. Cochran, 1754.

SMITH, Hugo. De sangurnis missione. Edinburgh: G. Hamilton & J. Balfour, 1755.

BRUCE, Alexander. De hydrophobia. Edinburgh: W. Sands, A. Murray & J. Cochran, 1755.

ALBINUS, Christiaan Bernard. Specimen anatomicum [reprint of a dissertation]. Leyden: Henricum Mulhovium, 1724.

BULFINCH, Thomas. De crisibus. Edinburgh: Hamilton, Balfour & Neill, 1757.

RAMSAY, Robert. De bile. Edinburgh: Hamilton, Balfour & Neill, 1757.

BAYLY, John. De frigore, quatenus morborum caussa. Edinburgh: Hamilton, Balfour & Neill, 1757.

ESTC T9090; Garrison & Morton 919; Bibliotheca Oslerana 1145 (1782 edition). Not in Norman. Guerlac, ‘Joseph Black and Fixed Air a Bicentenary Retrospective, with Some New or Little Known Material,’ Isis 48 (1957), pp. 124-151. Guerlac, ‘Joseph Black and Fixed Air: Part II,’ ibid., pp. 433-456. Ramsay, The Life and Letters of Joseph Black M.D., 1918.

8vo (185 x 115mm), pp. [Monroe:] [iv], 70; [Campbell:] [vi], 38; [Black:] [vi], 46; [Smith:] [iv], 36; [Bruce:] [iv], 56; [Albinus:] [1-2], 3-57, [1, blank]; [Bulfinch:] [iv], 21, [1, blank]; [Ramsay:] [iv], 20; [Bayly:] [ii], 31, [1, blank], with 22-leaf manuscript index of dissertation subjects with dates bound at rear, manuscript contents leaf at front (a little spotting or dust soiling throughout, half-title to Black’s dissertation partly detached). Contemporary calf (rubbed, joints and spine cracked and boards loosening, a little wear to extremities).

Item #5461

Price: $185,000.00