Chapter XV (4)

"It was felt by many philosophers, particularly by the illustrious Bergman, that an improvement in chemical nomenclature was necessary; and in 1787, MM. Lavoisier, Morveau, Berthollet, and Fourcroy, presented to the world a plan for an almost entire change in the denomination of chemical substances, founded upon the idea of calling simple bodies by some names characteristic of their most striking qualities, and of naming compound bodies from the elements which composed them." There was, besides, a secret feeling in the breasts of the associated chemists, which, no doubt, had its influence in suggesting and promoting such a scheme. The views of Lavoisier had so changed the face of chemistry, as almost to have rendered it a new science: by adopting a new nomenclature, they identified, as it were, all the discoveries of the day with the new theory, and thus appropriated to France the original and entire merit of the system.

It is impossible to pass over this subject without a comment. Lavoisier was unquestionably indebted to Dr. Black for the support, if not for the suggestion, of the most brilliant part of his theory of combustion; and yet he attempted even to conceal the name of the discoverer of _latent heat_.

How far Lavoisier was really culpable, and whether he did not intend to do full justice to all the claims of his predecessors, cannot now be known; as he was cut off in the midst of his career, while so many of his scientific projects remained unexecuted. From the posthumous works of Lavoisier, there is some reason for believing that, if he had lived, he would have done justice to all parties; but there is no doubt that Dr. Black, in the mean time, thought himself aggrieved by the publication of several of Lavoisier's papers in the "Mémoires de l'Académie," and that he formed the intention of doing himself justice, by publishing an account of his own discoveries: this intention, however, was unfortunately thwarted and prevented by bad health. But to return to the subject of nomenclature. Sir H. Davy continues--"The new nomenclature was speedily adopted in France; under some modifications, it was received in Germany; and, after much discussion and opposition, it became the language of a new and rising generation of chemists in England. It materially assisted the diffusion of the anti-phlogistic doctrine, and even facilitated the general acquisition of the science; and many of its details were contrived with much address, and were worthy of its celebrated authors."

On the general adoption of this new theory of chemistry, it must be admitted that its authors displayed an intemperate triumph wholly unworthy of them. They held a festival, at which Madame Lavoisier, in the habit of a priestess, burnt the works of Stahl on an altar erected for the occasion, while solemn music played a requiem to his departed system!

Sir Humphry Davy, in speaking of the merits of Lavoisier, observes that "he must be regarded as one of the most sagacious of the chemical philosophers of the last century; indeed, except Cavendish, there is no other enquirer who can be compared to him for precision of logic, extent of view, and sagacity of induction. His discoveries are few, but he reasoned with extraordinary correctness upon the labours of others. He introduced weight and measure, and strict accuracy of manipulation into all chemical processes. His mind was unbiassed by prejudice; his combinations were of the most philosophical nature; and in his investigations upon ponderable substances, he has entered the true path of experiment with cautious steps, following just analogies, and measuring hypotheses by their simple relations to facts."

It will be scarcely possible for a future generation of philosophers to imagine with what an undisciplined ardour the anti-phlogistic system, thus enhanced by a new and fascinating nomenclature, was supported throughout Europe. Facts only were appreciated in proportion to the evidence they furnished of its truth; and a discovery even required the sanction of its authority as the passport to notice and regard. The least expression of doubt, as to the validity of any point in its doctrines, exposed the sceptic to a host of assailants, and fortunate was he if he escaped the fate of Peter Ramus, or of those who ventured to question the infallibility of that great despot of another age, Aristotle.

In no country of Europe did this feeling manifest itself to a greater extent than in England. There was perhaps a political prejudice co-operating upon the occasion: it is very difficult, under any circumstances, to avoid connecting the man and his works. The fate of Lavoisier[133] was truly affecting, and by a species of retributive justice, he received the sympathy of the world in the homage paid to his system; while the atrocity of his assassination, on which every Englishman dwelt with horror, appeared to be thus heightened by every praise bestowed upon his merits.

[133] Lavoisier perished on the scaffold at the age of
fifty-one, during the sanguinary reign of Robespierre. The
fury of the revolutionary leaders of France was particularly
directed against the farmers-general of the revenue, who were
all executed, with the exception of a single individual, a M.
de Verdun. Sixty of them were guillotined at the same time,
in consequence of a report of Dupin, a frantic member of the
Convention. The revolutionary tribunal adopted a general formula,
as the ground of their condemnation, which is curious as applied
to Lavoisier, who was declared guilty of having "adulterated
snuff with water and ingredients destructive of the health of
the citizens." The unfortunate philosopher requested time to
complete some experiments on respiration. The reply of Coffinhal,
the President, was, that "the Republic did not want savans or
chemists, and that the course of justice could not be suspended."

It is not the least surprising circumstance in the history of this system, that with such a blind and idolatrous admiration of its principles, so few facts should have been distorted. It is true that, from the belief that combustion could never take place without the presence of oxygen, the elementary principle of Scheele became, according to these views, a compound of oxygen and an acid; and the name of _dephlogisticated marine acid_ was exchanged for that of _oxy-muriatic acid_, a circumstance which spread a cloud of error over the science, and perhaps retarded its progress in a greater degree than is generally imagined. In like manner, the chemist neglected to avail himself of the hint which, under other impressions, would have proved an important clue to discovery, _viz._ the acid properties of sulphuretted hydrogen.

We have now arrived at that stage in our history, when it may with propriety and advantage be asked--WHAT HAS DAVY DONE IN CORRECTING ERROR, OR IN ADVANCING TRUTH?

The answer to this question will be nothing more than a summary of those discoveries which have been successively investigated during the progress of the present work.

The new doctrines of chemistry were highly instrumental in encouraging more extended investigations into all the different productions of nature and art; and we may observe, that one of the first efforts of Sir Humphry Davy was to improve our knowledge of the nature and habitudes of the tanning and astringent principles of vegetables,--an enquiry which had been commenced by Seguin and Proust. In pursuing even the most beaten path, he was sure to discover objects of novelty. Look at his early experiments on the cane, and on the straw of wheat, barley, and hay, and we shall see how magically he raised from their ashes a new flower of knowledge. He soon, however, quitted the track of other experimentalists; although we learn from the whole tenor of his researches, that he could obey as well as he could command, and he could act in the ranks, although he more frequently appeared as a general in the field of science.

Sir Humphry Davy has observed, that "at the time when the anti-phlogistic theory was established, electricity had little or no relation to chemistry. The grand results of Franklin respecting the cause of lightning, had led many philosophers to conjecture, that certain chemical changes in the atmosphere might be connected with electrical phenomena; and electrical discharges had been employed by Cavendish, Priestley, and Van-Marum, for decomposing and igniting bodies; but it was not till the era of the wonderful discovery of Volta, in 1800, of a new electrical apparatus, that any great progress was made in chemical investigation by means of electrical combinations.

"Nothing tends so much to the advancement of knowledge as the application of a new instrument. The native intellectual powers of men in different times are not so much the causes of the different success of their labours, as the peculiar nature of the means and artificial resources in their possession. Independent of vessels of glass, there could have been no accurate manipulations in common chemistry: the air-pump was necessary for the investigation of the properties of gaseous matter; and without the Voltaic apparatus, there was no possibility of examining the relations of electrical polarities to chemical attractions."

There is a candour in this statement which we cannot but admire. Nor does the admission diminish the glory of him who, by the application of such new instruments of research, was enabled to penetrate into the hidden mysteries of Nature. What avails the telescope, without the eye of the observer?

To Davy, the Voltaic apparatus was the _golden branch_, by which he subdued the spirits that had opposed the advance of former philosophers; but what would its possession have availed him, had not his genius, like the ancient Sibyl, pointed out its use and application?

It will be seen that he was thus enabled, not only to discover laws which are in constant operation, modifying the forms of matter, and influencing all the operations of chemistry, but, by applying them, to determine the elements of the fixed alkalies to be oxygen and a metallic base: a fact obviously opposed to the idea of oxygen being the general principle of acidity; for here it was the principle of alkalinity, if it may be so expressed. This was shaking the corner-stone of the edifice, and his subsequent researches into the nature of oxy-muriatic acid may be said to have overthrown it; for if either of the elements of this body can be considered as the acidifier, it is hydrogen. The consequences which flowed from this truth were of the highest importance, not only in correcting errors, which the progress of discovery, instead of rectifying, was actually multiplying, but in leading to the developement of new bodies. Iodine might have been recognised as an elementary body; but its relations to oxygen and hydrogen would probably have remained unknown, had not a knowledge of the true character of chlorine assisted the enquiry.

The same observation will apply to the recently discovered body, Bromine. In like manner has the chemist been led, by the chloridic theory, to a more accurate acquaintance with the composition of the fluoric, hydriodic, and hydrocyanic acids; while he has also learnt that hydrogen alone can convert certain undecompounded bases into well characterised acids, without the aid of oxygen. The same discovery has completely changed all our opinions with regard to a very important series of saline combinations, and developed the existence of new compounds of a most interesting description.

Thus, then, has the _acidifying_ hypothesis of Lavoisier been overturned, and a new theory constructed out of its ruins, which acknowledges no distinct element as the one imparting to matter the characters of an acid.

Equally complete has been the downfall of the theory of combustion. The discovery of the true nature of chlorine was, in itself, sufficient to show that bodies might combine, with the phenomena of heat and light, without the presence of oxygen; but Davy has brought a mass of evidence from other sources in proof of the same truth. He has shown that, whenever the chemical forces which determine either composition or decomposition are energetically exercised, the phenomena of combustion, or incandescence, with a change of properties, are displayed. He has therefore annulled the distinction between supporters of combustion and combustibles, since he has shown that, in fact, one substance frequently acts in both capacities, being a supporter _apparently_ at one time, and a combustible at another. But in both cases the heat and light depend on the same cause, and merely indicate the energy and rapidity with which reciprocal attractions are exerted. Thus sulphuretted hydrogen is a combustible with oxygen and chlorine; a supporter with potassium. Sulphur, with chlorine and oxygen, has been called a combustible basis; with metals, it acts the part of a supporter. In like manner, potassium unites so powerfully with arsenic and tellurium, as to produce the phenomena of combustion. Nor can we ascribe the appearances to the liberation of latent heat, in consequence of condensation of volume. The protoxide of chlorine, a body destitute of any combustible constituent, at the instant of decomposition evolves light and heat with explosive violence; and its volume becomes one-fifth greater. Chloride and iodide of azote, compounds alike destitute of any inflammable matter, according to the ordinary belief, are resolved into their respective elements with tremendous force of inflammation; and the first expands into more than six hundred times its bulk. Now, instead of heat and light, a prodigious degree of _cold_ ought to accompany such an expansion, according to the hypothesis of latent heat. Other instances might be cited, and other arguments adduced on the same subject, but time and space fail me.[134]

[134] The reader who wishes for further details, will consult
with advantage the article Combustion in Dr. Ure's Dictionary of
Chemistry; a work to which I acknowledge myself much indebted on
this and other occasions.

Such, then, are the facts developed by the experimental researches of Sir Humphry Davy; from which it follows, that--

1. Combustion is not necessarily dependent on the agency of oxygen.

2. That it cannot be regarded as dependent upon any peculiar principle or form of matter, but must be considered as a general result of intense chemical action.

3. That the evolution of light and heat cannot be ascribed simply to a gas parting with its latent store of those ethereal fluids.

4. That, since all bodies which act powerfully upon each other are in the opposite electrical relations of positive and negative, the evolution of heat and light may depend upon the annihilation of these opposite states, which will happen whenever they combine.

Thus has Sir H. Davy, by refuting the opinions of the French philosophers, respecting the relations of oxygen to the phenomena of combustion, and the nature of its products, removed the pillars on which the fabric of the anti-phlogistic rested, and reduced the generalization of Lavoisier to isolated collections of facts; the sound logic, however,--the pure candour, the numerical precision of inference which characterise the labours of the French philosopher, will cause his name to be held in everlasting admiration. The downfall of his doctrine is the natural result of the progress of truth; the same fate may attend our present systems, but the facts discovered through their means are unchangeable and eternal; and it is upon them alone that the fame of the chemist must ultimately rest.

In sciences collateral to chemistry, the researches of Davy have cast a reflected lustre. In geology, his discovery of the composition of the earths, has opened a new path of investigation; while his examination of the water and gaseous matter so frequently enclosed in the cavities of quartz, has given no small degree of support to the hypothesis of the Plutonists; above all, his results connected with the decomposition and transfer of different elements by Voltaic influence, has already explained many phenomena relating to metallic veins; and the late researches of Mr. Fox must lead us to the conclusion, that electric powers are still in operation in the recesses of the earth; and that mineral veins are not only the cabinets of Nature, but still her active laboratories.

These cursory observations upon the discoveries of Sir H. Davy relate merely to the changes they have effected in the general theory of chemistry. I might recapitulate the numerous researches by which he has extended our knowledge upon particular subjects; but I have so fully entered into the consideration of them in the body of my work, that I consider such a tax upon the patience of my reader would be both unfair and unnecessary.

I shall therefore _conclude_ my long and arduous labour, by enumerating the different memoirs communicated by this distinguished philosopher to the Royal Society; and also the several works which he published at different periods of his brilliant but too fleeting career.

1. An Account of some Galvanic Combinations, formed by single
metallic plates and fluids, analogous to the Galvanic Apparatus
of M. Volta.

_Read June 18, 1801._

2. An Account of some Experiments and Observations on the
constituent parts of certain Astringent Vegetables, and on
their operation in Tanning.

_February 24, 1803._

3. An Account of some Analytical Experiments on a Mineral
Production from Devonshire, consisting principally of Alumina
and Water.

_February 28, 1805._

4. On a Method of analysing Stones containing a fixed Alkali,
by means of Boracic acid.

_May 16, 1805_.

* _For the above papers, the Society awarded him the Copley
Medal._

5. THE BAKERIAN LECTURE.--On some Chemical agencies of
Electricity.

_November 20, 1806._

** _For this memoir, he received the prize of the French
Institute._

6. THE BAKERIAN LECTURE.--On some new Phenomena of Chemical
Changes produced by Electricity, particularly the Decomposition
of the Fixed Alkalies, and the exhibition of the new substances
which constitute their bases; and on the general nature of
Alkaline bodies. 3?

_Read November 19, 1807._

7. Electro-chemical Researches on the Decomposition of the
Earths; with Observations on the Metals obtained from the
Alkaline Earths; and on the Amalgam procured from Ammonia.

_June 30, 1808._

8. THE BAKERIAN LECTURE.--An Account of some new Analytical
Researches on the nature of certain bodies, particularly the
Alkalies, Phosphorus, Sulphur, Carbonaceous matter, and the
Acids hitherto uncompounded; with some general Observations on
Chemical Theory.

_December 15, 1808._

9. New Analytical Researches on the nature of certain bodies;
being an Appendix to the Bakerian Lecture for 1808.

_February 1809._

10. THE BAKERIAN LECTURE FOR 1809. On some new Electro-chemical
Researches on various objects, particularly the metallic bodies
from the Alkalies and Earths; and on some combinations of
Hydrogen.

_November 16, 1809._

11. Researches on the Oxy-muriatic Acid, its nature and
combinations; and on the elements of Muriatic Acid; with some
Experiments on Sulphur and Phosphorus, made in the Laboratory
of the Royal Institution.

_Read July 12, 1810._

12. THE BAKERIAN LECTURE FOR 1810. On some of the Combinations
of Oxy-muriatic Gas and Oxygen, and on the chemical relations
of those principles to inflammable bodies.

_November 15, 1810._

13. On a Combination of Oxy-muriatic Gas and Oxygen Gas.

_February 21, 1811._

14. On some Combinations of Phosphorus and Sulphur, and on some
other subjects of Chemical Enquiry.

_June 18, 1812._

15. On a new Detonating Compound; in a letter to Sir Joseph
Banks, Bart. F.R.S.

_November 5, 1812._

16. Some further Observations on a new Detonating substance.

_July 1, 1813._

17. Some Experiments and Observations on the Substances
produced in different chemical processes on Fluor Spar.

_July 8, 1813._

18. An Account of some New Experiments on the Fluoric
Compounds; with some Observations on other objects of Chemical
Enquiry.

_February 13, 1814._

19. Some Experiments and Observations on a new Substance, which
becomes a Violet-coloured Gas by heat.

_January 20, 1814._

20. Further Experiments and Observations on Iodine.

_Read June 16, 1814._

21. Some Experiments on the Combustion of the Diamond, and
other Carbonaceous Substances.

_June 23, 1814._

22. Some Experiments and Observations on the Colours used in
Painting by the Ancients.

_February 23, 1815._

23. Some Experiments on a solid Compound of Iodine and Oxygen,
and on its Chemical Agencies.

_April 20, 1815._

24. On the Action of Acid upon the Salts usually called
_Hyper-Oxymuriates_, and on the Gases produced from them.

_May 4, 1815._

25. On the _Fire-damp_ of Coal Mines, and on methods of
lighting the Mine, so as to prevent Explosion.

_November 19, 1815._

26. An Account of an Invention for giving Light in Explosive
Mixtures of _Fire-damp_ in Coal Mines, by consuming the
Fire-damp.

_January 11, 1816._

27. Further Experiments on the Combustion of Explosive Mixtures
confined by Wire Gauze, with some Observations on Flame.

_January 25, 1816._

28. Some Researches on Flame.

_January 16, 1817._

29. Some New Experiments and Observations on the Combustion of
Gaseous Mixtures; with an account of a method of preserving
a continued Light in Mixtures of inflammable Gases and Air,
without Flame.

_Read January 23, 1817._

*** _For the preceding five papers, the Rumford Medals were
awarded to him._

30. On the fallacy of Experiments in which Water is said to
have been formed by the decomposition of Chlorine.

_February 12, 1818._

31. New Experiments on some of the combinations of Phosphorus.

_April 9, 1818._

32. Some Observations on the formation of Mists in particular
situations.

_February 25, 1819._

33. On the Magnetic Phenomena produced by Electricity.

_November 16, 1820._

34. Some Observations and Experiments on the Papyri found in
the ruins of Herculaneum.

_March 15, 1821._

35. Further Researches on the Magnetic Phenomena produced by
Electricity; with some new Experiments on the properties of
Electrified bodies, in their relations to conducting powers and
temperature.

_July 5, 1821._

36. On the Electrical Phenomena exhibited _in vacuo_.

_December 20, 1821._

37. On the state of Water and Aëriform matter in cavities
found in certain Crystals.

_Read June 13, 1822._

38. On a new Phenomenon of Electro-Magnetism.

_March 6, 1823._

39. On the application of Liquids formed by the condensation of
Gases, as mechanical Agents.

_April 17, 1823._

40. On the changes of volume produced in Gases, in different
states of density, by Heat.

_May 1, 1823._

41. On the Corrosion of Copper Sheathing by sea-water; and on
methods of preventing this effect, and on their application to
ships of war and other ships.

_Jan. 24, 1824._

42. Additional Experiments and Observations on the application
of Electrical Combinations to the preservation of the Copper
Sheathing of ships, and to other purposes.

_June 17, 1824._

43. Further Researches on the preservation of Metals by
Electro-chemical means.

_June 9, 1825._

44. THE BAKERIAN LECTURE for 1826.--On the Relation of
Electrical and Chemical changes.

_June 3, 1826._

**** _For this memoir, the Royal Society conferred upon him the
Royal Medal._

45. On the Phenomena of Volcanoes.

_March 20, 1828._

46. Account of some Experiments on the Torpedo.

_November 20, 1828._

HIS PUBLISHED WORKS ARE,

"Experimental Essays on Heat, Light, and on the Combinations of Light, with a new Theory of Respiration," &c. Published in _Contributions to Physical and Medical Knowledge, by T. Beddoes, M.D._ 1799.

"Researches Chemical and Philosophical, chiefly concerning Nitrous Oxide, and its Respiration." 1800.

"A Syllabus of a Course of Lectures."

"An Introductory Lecture." 1801.

"Elements of Chemical Philosophy." 1812.

"Elements of Agricultural Chemistry." 1813.

"On the Safety Lamp for Coal Miners; with some Researches on Flame." 1818. (Several Editions.)

"Salmonia; or Days of Fly-Fishing."

"Consolations in Travel; or the Last Days of a Philosopher."

APPENDIX.