DR JOSEPH, distinguished for his discoveries in chemistry, was born in France, on the banks of the Garonne in the year 1728. His father was a native of Belfast, but descended from a Scotch family who had been some time settled there. Mr Black, the father, was engaged in the wine trade; and for the purpose of carrying it on, he resided chiefly at Bordeaux.

He is represented as a man of extensive information, of candid and liberal sentiments, and of amiable manners; but particularly distinguished by the strength of his attachments and the warmth of his heart. These amiable and estimable qualities in the character of Mr Black, attracted the attention, and procured the friendship and intimacy of the discerning and benevolent Montesquieu, who was one of the presidents of the court of justice in the province while Mr Black resided at Bordeaux. Letters and fragments of correspondence between the president and Mr Black are still preserved in the family, as precious relics and memorials of the intercourse, honourable to both, which subsisted between that great man and their ancestor.

Some time before Mr Black retired from business, he sent his son Joseph, then in his twelfth year, to Belfast, on account of his education. And having completed the usual course of instruction in a grammar school, he was sent to the university of Glasgow in the year 1746. During the time which he studied at that seminary, his attention seems to have been chiefly directed to physical science; and he became a favourite pupil of Dr Dick, then professor of natural philosophy. When Dr Black had finished the ordinary course of general study at the university, he made choice of the profession of medicine; and he directed his views to those pursuits and studies which were necessary to qualify him for that profession.

It was about this time that Dr Cullen had been appointed to the lectureship of chemistry in the university of Glasgow. Hitherto this science had been only treated as a curious and in some respect a useful art. This great man, conscious of his own strength, and taking a wide and comprehensive view, saw the unoccupied field of philosophical chemistry open before him. He was satisfied that it was susceptible of great improvement by means of liberal inquiry and rational investigation. He was therefore determined to enter the unbeaten path, and to lead his followers to those unexplored regions which are included in the wide ranges of this comprehensive and attractive science. It was at this time that Dr Black became the pupil of Dr Cullen; and it was perhaps to this fortunate coincidence that Dr Black was indebted for the foundation of his future reputation as a philosopher and a chemist. The liberal and extensive views of Cullen happily accorded with the enlarged habits of thought which the young philosopher had previously acquired. Dr Cullen took a deep interest in the progress of his students. He delighted in encouraging and aiding their efforts; and therefore perceiving the bias of Black's pursuits, soon attached him to himself. And by the intercourse and intimacy which followed he was led into the same train of thought, and conducted into the same course of studies. He was received into a closer connexion, and became a valuable assistant in all Dr Cullen's chemical operations. The experiments of Black were frequently adduced to prove facts which were stated in the lecture, and they were considered as good authority. Thus commenced a mutual confidence and friendship which was highly honourable to both, and was never afterwards mentioned by Dr Black but with gratitude and respect.

In the year 1751 Dr Black went to Edinburgh to complete the course of his medical studies. There he resided in the house of his cousin-german, Mr Ruscel, professor of natural philosophy in that university, a gentleman of enlarged views and liberal sentiments, whose conversation and studies must have been both agreeable and profitable to his young friend.

At this time the mode of action of lithontriptic medicines, but particularly lime-water, in alleviating the pains of stone and gravel, divided the opinions of professors and practitioners. This subject became extremely interesting both to the physician and chemist. And as it is usual for the students to enter warmly into those discussions which give rise to much difference of opinion among the teachers, this subject, quite suited to his taste, particularly attracted and interested the attention of Mr Black, who was then one of Dr Cullen's most zealous and intelligent pupils. It appears from some of his memorandums, that he at first held the opinion that the causticity of alkalies is owing to the igneous matter which they derive from quicklime. But having prosecuted his experiments on magnesia, this grand secret of nature was laid open to his view. This led him to conclude, that the acrimony of these substances was not owing to their combination with igneous particles; that it was their peculiar property; and that they lost this property and became mild, by combining with a certain portion of air, to which he gave the name of fixed air; because it was fixed or became solid in the substances in the composition of which it entered.

This grand discovery, which forms one of the most important eras of chemical science, was the subject of his inaugural dissertation, published at the time that he was admitted to his medical degree in the university of Edinburgh. He had not availed himself of the time he had studied at Glasgow, but took the whole course prescribed by the rules of the university. This delay, it has been supposed, may have been owing to the investigation of the subject in which he had engaged not having been completed, which determined him to proceed with caution, till he had established his doctrine by a train of decisive experiments.

About the time that Dr Black obtained his medical degree, Dr Cullen was removed to Edinburgh, which made a vacancy in the chemical chair at Glasgow. While he remained at that university, Dr Black had been a diligent and attentive student; and the discovery published in his inaugural essay had added much to his reputation. He was therefore looked up to as a person amply qualified to fill the vacant chair; and accordingly, in the year 1756, he was appointed professor of anatomy, and lecturer on chemistry in the university of Glasgow. And it was perhaps fortunate for himself, fortunate for the public and for science, that a situation so favourable presented itself, a situation which allowed him full time to dedicate his talents chiefly to the cultivation of chemistry, which had now become his favourite science.

Along with the lectureship on chemistry, Dr Black's first appointment in the university of Glasgow was to the professorship of anatomy. The latter branch of medical study was either not so suitable to his taste, or he did not consider himself so well qualified to be useful in it; for soon after, arrangements were made with the professor of medicine, by which the professors exchanged departments, when Dr Black undertook that of the institutes and practice of medicine.

At this time, his lectures on medicine formed his chief talk. And the perspicuity and simplicity, the caution and moderation which he discovered in the doctrines which he delivered, gave great satisfaction. The time and attention which were occupied in these lectures, and in the medical practice in some measure necessarily connected with his situation, are supposed by some to have been the principal cause of Dr Black's having suddenly stopped short in that brilliant career on which he at first so successfully entered. It is, however, more probable, that the calm and unambitious temper which seems to have been a striking feature of his character, and which a less friendly hand than his learned biographer would have set down as nearly allied to indolence, checked the spirit of ardour and perseverance which was necessary to encourage and carry him forward in the path of discovery and research. Whatever may have been the cause, it is to be regretted, that Dr Black, so conspicuous for his patient, judicious, and elegant mode of investigation, and so distinguished for the simplicity, perspicuity, and precision of his reasonings and deductions, should have contributed so little in rearing the noble superstructure of chemical science, the foundation of which he had been the means of establishing on a firm and solid basis. The theory of the nature of quicklime, and the cause of its causticity, was soon known to the German chemists, and from them it met with strong opposition. Various mysterious doctrines at this time prevailed in the German schools concerning the peculiar nature of fire. As their notions of the causticity of alkaline substances involved some of these doctrines, a great many objections were started to a theory which threatened to overthrow long established and favourite opinions. The most formidable opponent to the new theory was Professor Meyer of Osnaburgh. All the phenomena of the causticity and mildness of lime and alkalies, were, according to his explanation, to be accounted for, by the action of a substance of a peculiar nature, to which he gave the name of acidum pingue. This substance, which was supposed to be formed in the lime during calcination, consisted of an igneous matter in a certain state of combination with other substances. It is a matter of some surprise that Dr Black should have experienced any uneasiness on account of the opposition made to his discovery by mere hypothesis unsupported by facts or even by plausible argument, when his own doctrine had been fully and irrefragably established by the sure test of decisive experiment. Nor is it less surprising, that he should have taken great pains for several years in the course of his lectures, in refuting the arguments and in combating the objections of Meyer to his own theory.

Dr Black's reception at the university of Glasgow was highly flattering and encouraging. As a student, he had not only done himself much credit by his successful progress in the different pursuits in which he was engaged, but he had also during his residence there conciliated the attachment and affection of the professors in a high degree. When he returned as a professor, he was immediately connected in the strictest friendship with Dr Adam Smith, then professor of moral philosophy in that university. And this friendship, which now commenced, grew stronger and stronger, and was never interrupted through the whole of their lives. A simplicity and sensibility, an incorruptible integrity, the strictest delicacy and correctness of manners, marked the character of each of the philosophers, and firmly bound them in the closest union.

At Glasgow, Dr Black soon acquired great reputation as a professor, and became a favourite physician in that large and active city. His engaging countenance, his agreeable and attractive manners, free from all studied endeavour to please, and the kind concern he took in the cases intrusted to his care, made him a most welcome visitor in every family.

It was between the years 1759 and 1763, that he brought to maturity his speculations concerning heat, which had occupied his attention at intervals, from the very first dawn of his philosophical investigations. His discoveries in this department of science were by far the most important of all that he made, and perhaps indeed the most valuable which appeared during the busy period of the 18th century. To enter fully into the nature of his investigations would be improper in this place; but the sum of them all was usually expressed by him in the following propositions.

When a solid body is converted into a fluid, there enters into it and unites with it, a quantity of heat, the presence of which is not indicated by the thermometer, and this combination is the cause of the fluidity which the body assumes. On the other hand, when a fluid body is converted into a solid, a quantity of heat separates from it, the presence of which was not formerly indicated by the thermometer. And this separation is the cause of the solid form which the fluid assumes.

When a liquid body is raised to the boiling temperature, by the continued and copious application of heat, its particles suddenly attract to themselves a great quantity of heat, and by this combination their mutual relation is so changed that they no longer attract each other, but are converted into an elastic fluid like air. On the other hand, when these elastic fluids, either by condensation or by the application of cold bodies, are reconverted into liquids, they give out a vast quantity of heat, the presence of which was not formerly indicated by the thermometer.

Thus water when converted into ice gives out \(140^\circ\) of heat, and ice when converted into water absorbs \(140^\circ\) of heat, and water when converted into steam absorbs about \(1000^\circ\) of heat without becoming sensibly hotter than \(212^\circ\). Philosophers had been long accustomed to consider the thermometer as the surest method of detecting heat in bodies, yet this instrument gives no indication of the \(140^\circ\) of heat which enter into air when it is converted into water, nor of the \(1000^\circ\) which combine with water when it is converted into steam. Dr Black, therefore, said that the heat is concealed (later) in the water and steam, and he briefly expressed this fact by calling the heat in that case latent heat.

Dr Black having established this discovery by simple and decisive experiments, drew up an account of the whole investigation, and read it to a literary society which met every Friday, in the faculty-room of the college, consisting of the members of the university, and several gentlemen of the city who had a relish for philosophy and literature. This was done April 23, 1762, as appears by the registers. This doctrine was immediately applied by its author to the explanation of a vast number of natural phenomena, and in his experimental investigations he was greatly assisted by his two celebrated pupils Mr Watt and Dr Irvine.

As Dr Black never published an account of his doctrine of latent heat, though he detailed it every year subsequent to 1762 in his lectures, which were frequented by men of science from all parts of Europe; it became known only through that channel, and this gave an opportunity to others to pilfer it from him piece-meal. Dr Crawford's ideas respecting the capacity of bodies for heat, were originally derived from Dr Black, who first pointed out the method of investigating that subject.

The investigations of Lavoisier and Laplace concerning heat, published many years after, were obviously borrowed from Dr Black, and indeed consisted in the repetition of the very experiments, which he had suggested. Yet these philosophers never mention Dr Black at all: every thing in their dissertation assumes the air of originality; and indeed they appear to have been at great pains to prevent the opinions and discoveries of Dr Black from being known among their countrymen. But perhaps the most extraordinary procedure was that of Mr Deluc; this philosopher had expressed Black expressed his admiration of Dr. Black's theory of latent heat, and had offered to become his editor. Dr. Black, after much entreaty, at last consented, and the proper information was communicated to Mr. Deluc. At last the Idées sur la Meteorologie of that philosopher appeared in 1788. But what was the astonishment of Dr. Black and his friends, when they found the doctrine claimed by Deluc as his own, and an expression of satisfaction at the knowledge which he had acquired of Dr. Black's coincidence with him in opinion! (M. Deluc has published an answer to this charge in his own vindication. See Edin. Rev. No. 12, 1805.)

Dr. Black continued in the university of Glasgow from 1756 to 1766. In 1766 Dr. Cullen was appointed professor of medicine in the university of Edinburgh, and thus a vacancy was made in the chemical chair of that university. Dr. Black was with universal consent appointed his successor. In this new scene his talents were more conspicuous, and more extensively useful. He saw this, and while he could not but be highly gratified by the great concourse of pupils which the high reputation of the medical school of Edinburgh brought to his lectures, his mind was forcibly impressed by the importance of his duties as a teacher. This had an effect which perhaps was on the whole rather unfortunate. He directed his whole attention to his lectures, and his object was to make them so plain that they should be adapted to the capacity of the most illiterate of his hearers. The improvement of the science seems to have been laid aside by him altogether. Never did any man succeed more completely. His pupils were not only instructed but delighted. Many became his pupils merely in order to be pleased. This contributed greatly to extend the knowledge of chemistry. It became in Edinburgh a fashionable part of the accomplishment of a gentleman.

Perhaps also the delicacy of his constitution precluded him from exertion; the slightest cold, the most trifling approach to repletion, immediately affected his breast, occasioned feverishness, and if continued for two or three days brought on a spitting of blood. Nothing restored him but relaxation of thought and gentle exercise. The sedentary life to which study confined him was manifestly hurtful, and he never allowed himself to indulge in any intense thinking without finding these complaints sensibly increased.

So completely trammeled was he in this respect, that although his friends saw others distinguished enough to avail themselves of the novelties announced by Dr. Black in his lectures, and therefore repeatedly urged him to publish an account of what he had done, this remained unaccomplished to the last. Dr. Black often began the task, but was so nice in his notions of the manner in which it should be executed, that the pains he took in forming a plan of the work, never failed to affect his health, and oblige him to desist. Indeed he peculiarly disliked appearing as an author. His inaugural dissertation was the work of duty. His Experiments on Magnesia, Quicklime, and other alkaline substances, was necessary to put what he had indicated in his inaugural dissertations on a proper foundation. His Observations on the more ready freezing of Water that has been boiled, published in the Philosophical Transactions for 1774, was also called for; and his Analysis of the Waters of some Boiling Springs in Iceland, made at the request of his friend T. I. Stanley, Esq. was read to the Royal Society of Edinburgh, and published by the council. And these are the only works of his which have appeared in print.

The aspect of Dr. Black was comely and interesting. His countenance exhibited that pleasing expression of inward satisfaction, which, by giving ease to the beholder, never fails to please. His manner was unaffected and graceful. He was affable, and readily entered into conversation, whether serious or trivial. He was a stranger to none of the elegant accomplishments of life. He had a fine musical ear, with a voice which would obey it in the most perfect manner; for he sung, and performed on the flute, with great taste and feeling, and could sing a plain air at sight, which many instrumental performers cannot do. Without having studied drawing, he had acquired a considerable power of expressing with his pencil, and seemed in this respect to have the talents of a history painter. Figure indeed of every kind attracted his attention. Even a retort, or a crucible, was to his eye an example of beauty or deformity.

He had the strongest claim to the appellation of a man of propriety and correctness. Every thing was done in its proper season, and he ever seemed to have leisure in store. He loved society, and felt himself beloved in it; never did he lose a single friend, except by the stroke of death.

His only apprehension was that of a long continued sick bed, lest perhaps from any selfish feeling, than from the consideration of the trouble and distress which it would occasion to attending friends: and never was this generous wish more completely gratified. On the 26th Nov. 1799, and in the 71st year of his age, he expired without any convulsions, shock, or stupor, to announce or retard the approach of death. Being at table with his usual fare, some bread, a few prunes, and a measured quantity of milk diluted with water, and having the cup in his hand, when the last stroke of the pulse was to be given, he set it down on his knees which were joined together, and kept it steady with his hand in the manner of a person perfectly at ease; and in this attitude expired without spilling a drop, and without a writh in his countenance, as if an experiment had been required to show to his friends the facility with which he departed. His servant opened the door to tell him that some one had left his name; but getting no answer, stepped about half-way towards him, and seeing him sitting in that easy posture, supporting his bason of milk with one hand, he thought that he had dropt asleep, which sometimes happened after his meals. He went back and shut the door, but before he went down stairs, some anxiety which he could not account for, made him return again and look at his master. Even then he was satisfied after coming pretty near him, and turned to go away; but returning again, and coming close up to him, he found him without life. (Preface to Black's Lect. by Dr Robison.)

well known colour, supposed to be owing to the absence of light, most of the rays falling upon black substances being not reflected but absorbed by them. Concerning the peculiar structure of such bodies as fits them for appearing of this or that particular colour, see Colour and Dyeing. Black-Act. BLACK-Act; the statute of 9 Geo. I. c. 22. is commonly called the Waltham black act, because it was occasioned by the devastations committed near Waltham in Essex, by persons in disguise, or with their faces blacked. By this statute it is enacted, that persons hunting armed and disguised, and killing or stealing deer, or robbing warrens, or stealing fish out of any river, &c. or any persons unlawfully hunting in his majesty's forests, &c. or breaking down the head of any fish-pond, or killing, &c. of cattle, or cutting down trees or setting fire to house, barn, or wood, or shooting at any person, or sending letters either anonymous or signed with a fictitious name demanding money, &c. or refusing such offenders, are guilty of felony, without benefit of clergy. This act is made perpetual by 31 Geo. II. c. 42.

BLACK-Bird. See TURDUS, ORNITHOLOGY Index.

BLACK-Book of the Exchequer. See EXCHEQUER.

BLACK-Books, a name given to those which treat of necromancy, or, as some call it, negromancy. The black-book of the English monasteries was a detail of the scandalous enormities practised in religious houses, compiled by order of the visitors under King Hen. VIII. to blacken, and thus hasten their dissolution.

BLACK-Cap. See MOTACILLA, ORNITHOLOGY Index.

BLACK-Cock. See TETRAO, ORNITHOLOGY Index.

BLACK-Eagle. See FALCO, ORNITHOLOGY Index.

BLACK-Eunuchs, in the customs of the eastern nations, are Ethiopians castrated, to whom their princes commonly commit the care of their women. See ENUCH.

BLACK-Foreft, a forest of Germany, in Swabia, running from north to south between Ortnau, Brilgaw, part of the duchy of Wirtemberg, the principality of Fultenburg towards the source of the Danube, as far as the Rhine above Bafil. It is part of the ancient Hercynian forest.

BLACK-Friars, a name given to the Dominican order; called also predicants and preaching friars; in France, Jacobins.

BLACK-Jack, or Blende, is a mineral also called false galena, blinde, &c. See BLENDE, MINERALOGY Index.

BLACK-Land, in Agriculture, a term by which the husbandmen denote a particular sort of clayey soil, which, however, they know more by its other properties than by its colour, which is rarely any thing like a true black, and often but a pale gray. This, however pale when dry, always blackens by means of rains, and when ploughed up at these seasons it sticks to the ploughshares, and the more it is wrought the muddier and dustier coloured it appears. This sort of soil always contains a large quantity of sand, and usually a great number of small white stones.

BLACK Lead. See PLUMBAGO, MINERALOGY Index.

BLACK-Leather, is that which has passed the curriers hands, where, from the rust as it was left by the tanners, it is become black, by having been scored and rubbed three times on the grain-side with copperas water. See LEATHER.

BLACK-Legs, a name given in Leicestershire to a disease frequent among calves and sheep. It is a kind of jelly which settles in their legs, and often in the neck, between the skin and flesh.

VOL. III. Part II.

BLACK-Mail, a certain rate of money, corn, cattle, or other matter, anciently paid by the inhabitants of towns in Westmoreland, Cumberland, Northumberland, and Durham, to divers persons inhabiting on or near the borders, being men of name, and allied with others in those parts, known to be great robbers and spoil-takers; in order to be by them freed and protected from any pillage. Prohibited by 43 Eliz. c. 13. The origin of this word is much contested, yet there is ground to hold the word black to be here a corruption of blank or white, and consequently to signify a rent paid in a small copper coin called blanks. This may receive some light from a phrase still used in Picardy, where speaking of a person who has not a single halfpenny, they say, il n'a pas une blanque maille.

BLACK-Monks, a denomination given to the Benedictines, called in Latin nigri monachi, or nigro-monachi; sometimes ordo nigrorum, "the order of blacks."

BLACK-Outs. See OATS.

BLACK-Procession, in ecclesiastical writers, that which is made in black habits, and with black ensigns and ornaments. See PROCESSION. Anciently at Malta there was a black procession every Friday, where the whole clergy walked with their faces covered with a black veil.

BLACK-Rent, the same with black-mail, supposed to be rents formerly paid in provisions and flesh, not in specie.

BLACK-Rod. See ROD.

BLACK-Row Grains, a species of iron-stone or ore found in the mines about Dudley in Staffordshire.

BLACK Sea. See EUXINE-Sea.

BLACK-Sheep, in the oriental history, the ensign or standard of a race of Turcomans settled in Armenia and Mesopotamia; hence called the dynasty of the black sheep.

BLACK Stones and Gems, according to Dr Woodward, owe their colour to a mixture of tin in their composition.

BLACK-Strakes, a range of planks immediately above the wales in a ship's side. They are always covered with a mixture of tar and lamp black.

BLACK-Tin, in Mineralogy, a denomination given to the tin ore when dressed, stamped, and washed ready for the blowing-house, or to be melted into metal. It is prepared into this state by means of beating and washing; and when it has passed through several puddles or washing-troughs, it is taken up in form of a black powder, like fine sand, called black-tin.

BLACK-Wadd, in Mineralogy, a kind of ore of manganese, remarkable for its property of taking fire when mixed with linseed oil in a certain proportion. It is found in Derbyshire, and is used as a drying ingredient in paints; for when ground with a large quantity of oily matter it loses the property above mentioned. See MANGANESE, MINERALOGY Index.

BLACK-Water, the name of two rivers in Ireland; one of which runs through the counties of Cork and Waterford, and falls into Youghal bay; and the other, after watering the county of Armagh, falls into Lough-Neagh.

BLACK-Whytlof, in our old writers, bread of a middle fineness betwixt white and brown, called in some parts ravel-bread. In religious houses, it was the bread made made for ordinary guests, and distinguished from their household loaf, or panis conventualis, which was pure manchet, or white bread.

BLACK-Work, iron wrought by the blacksmiths; thus called by way of opposition to that wrought by whitesmiths.