equal bulk of solid food; while the necessity of expelling the excess above the actual wants of the system may in the latter case be productive of evil.'

With such a decided preference for the soup form of food as Count Rumford had been led to entertain, it is not to be wondered at that soup was an essential feature in all his schemes for the benefit of the poor. Soup was the great article of food employed in his experiments in Munich; and in his contemplated project of public kitchens and dining-rooms for large towns, the necessary condition of success was, that soup should be the staple diet. He even went into the details of the composition of soup; and his Essays contain recipes for making various kinds of soup, with and without butcher-meat. The following judicious observations of Rumford's American biographer seem to sum up both the merits and the demerits of these experiments and speculations: 'The only question which admits of doubt is, how the description of food preferred by Rumford is adapted to the circumstances of all countries. Now, to the greater part of the Anglo-Saxon race, soup, if not an abomination, will never be received as the staple of more than one daily meal; while tea and coffee, whose use Rumford reprobates, with their accompaniment of sugar, have become necessaries of life. In Paris, soup, which became for a while the fashionable mode of administering charity, was well adapted to the habits of the people; but in England and America it was received with grumbling, or rejected by all who could in any other mode obtain food. One reason no doubt was, that it was considered sufficient to make the food nutritious, without attempting to make it pleasing to the palate. This defect is far from inherent; for the soups of Rumford, whether containing none but vegetable matter, or a mixture of animal substance, may be easily rendered as delicious as the most costly preparations of the French kitchen.'

Besides the general schemes which we have mentioned, Count Rumford was engaged, during his residence in Bavaria, in many minor plans of social improvement; indeed, as we have already said, he acted the part of surveyor-general of the abuses of the electorate. It was not in the nature of things that he should be able to proceed in his various innovations and reforms without provoking some jealousy and opposition among the Bavarian nobles: the support and favour, however, of the elector never failed him, and with the people at large he was exceedingly popular. In the year 1794, finding his health greatly impaired by his close attention to business, he obtained leave of absence from the elector, and employed sixteen months in travelling through various parts of the continent, especially Italy. During his absence, two very gratifying testimonies of respect and gratitude were borne to him by the Bavarians. The first was, the erection of a monument to commemorate his public services. The other was still more honourable to him: it was the

resolution, already referred to, of the inmates of the Military Workhouse, when they heard that he was dangerously ill at Naples, to set apart an hour every evening to pray for his recovery. In 1795, Rumford returned to Bavaria, but left it almost immediately, to proceed on a visit to England. Here he was received with all distinction, and his opinion and advice were asked by all engaged in philanthropic schemes. To save himself the labour thus entailed upon him, he resolved to publish an account of his doings and experiments in Bavaria, and accordingly prepared for the press the two volumes of Essays which go by his name. The only subject of general interest in these Essays, apart from the purely scientific disquisitions, which remains to be mentioned by us, is that of fuel. In undertaking to reform chimneys and fire-places, Count Rumford had three objects in view-the saving of fuel, the prevention of smoke, and the avoidance of the injury to health arising from draughts. The extent of his services in this unpretending but most important department will be better estimated if we consider the state of fire-places in most European countries seventy or eighty years ago. The most polished nations of antiquity,' says Dr Renwick, 'had no other means of providing for the issue of the smoke of their fires than by leaving openings in the roof. They indeed appear, in some instances, to have heated apartments by flues circulating beneath the floors, which must have terminated in a vertical funnel, thus forming an approximation to the chimney; but there appears to be no instance of the arrangement of an open hearth and vertical flue until late in the middle ages. Chimneys and fire-places of the latter date are still to be seen in the kitchens and halls of baronial mansions; but the hearths were of great size, the arched openings wide and lofty, insomuch that they could be entered by persons standing upright, and admitted seats to be placed on each side of the fire. The latter, indeed, were the only places where the warmth of the fire could be enjoyed without exposure to the currents of cold air continually rushing in to join the ascending column in the chimney. Even when an increasing scarcity of fuel compelled less extravagant modes of applying it to be sought, the arched opening remained of a large size, the fire-place of a depth equal in extent to its front, and the walls were carried back perpendicularly to the latter. In England, where coal had come into almost universal use as a fuel, the grates in which it was burned were almost exact cubes, and were lined with cast-iron on the sides and back. The evils of these fire-places may be recollected by all whose age reaches sixty or seventy; and they are remembered with feelings in which shuddering and scorching are strangely combined, but which are almost unknown, and scarcely

Essays Political, Economical, and Philosophical. By Benjamin, Count of Rumford, Knight of the Orders of the White Eagle and St Stanislaus; Chamberlain, Privy-councillor of State, and Lieutenant-general in the Service of his Most Serene Highness the Elector Palatine, reigning Duke of Bavaria, &c.

to be imagined, by the present generation. Chimneys which did not smoke were the exception to the general rule; and the exposure of the surface of the body to cold currents generated the acute pains of rheumatism; while the frequent alternations of an increased and checked perspiration caused colds, to be followed, in regular course, by pulmonary complaints. In this state of things Rumford undertook to remedy the manifold evils of the open fire-place.'

Observing that the heat of a mass of blazing fuel in a grate consisted of two parts-that which radiated into the room, and served the purposes of warmth; and that which, by heating the column of air in the chimney, caused it to ascend, Rumford saw that an enormous saving could be effected by diminishing the size of the grate. Instead of a cubical mass of fuel, such as was generally used, he proposed to employ a grate of ordinarily broad front, but not deep backward, and with the sides not perpendicular to the front, but inclining. The effect of this was to limit the fire to the single function of warming the room by radiation from its front, while the mass of coal which had formerly been consumed without any benefit to the apartment was saved. In order, however, to prevent the smoking of the chimneys which would have arisen from this diminution of the burning mass, another change was necessary; and this was the narrowing the throat of the chimney, so as to allow no more air to pass through it than the precise quantity required to maintain the combustion. The immoderate size of the throats of chimneys,' says Rumford, 'is the great fault of their construction. It is this fault which ought always first to be attended to in every attempt which is made to improve them; for however perfect the construction of a fire-place may be in other respects, if the opening left for the passage of the smoke is larger than is necessary for that purpose, nothing can prevent the warm air of the room from escaping through it; and whenever this happens, there is not only an unnecessary loss of heat, but the warm air which leaves the room to go up the chimney being replaced by cold air from without, draughts of cold air cannot fail to be produced in the room, to the great annoyance of those who inhabit it.'

Such is a general description of Count Rumford's alterations in fire-places. The subject, however, was pursued by him to its minutest details, and illustrated by numerous and specific plans for curing smoky chimneys under all possible circumstances. He likewise invented various forms of stoves and grates, intended to exhibit the model perfection of an apparatus for heating rooms or for cooking victuals. So thorough and complete was his investigation of the subject, that little remained afterwards to be added to his conclusions; and it may be said, that any case of the continuance of a smoky chimney after the publication of his Essays arose from a neglect or misapplication of the principles there developed.

The investigation of the subject of the construction of grates and

fire-places led Rumford to researches on heat, which ultimately assumed an almost purely scientific character. It is indeed a feature worthy of remark in Count Rumford's life, that, unlike the greater number of eminent scientific men, he did not begin by attention to the abstract doctrines of science, and carry these out into practical application, but he was led originally to a consideration of the doctrines through his desire of practical improvement. Always exhibiting scientific tendencies and talents, the circumstances of his life were such as to demand constant practical activity and a sacrifice of his purely scientific aspirations to present utility; and it was only in the latter part of his life that his inquiries and studies assumed an abstract character. The most important of these inquiries were in relation to heat, light, and the projectile force of gunpowder; but as an enumeration of Rumford's scientific discoveries, or an examination of his claims to be considered a scientific discoverer, would be beyond the scope of the present Tract, we shall only mention that Count Rumford is entitled to the honour of having been the first to explain the manner in which heat is propagated in fluids, having demonstrated that the boiling of water over a fire takes place, not in consequence of the travelling of the heat upwards through the fluid by conduction, but in consequence of the perpetual circulation of the particles of the fluid themselves, the heated particles rising, and the cooler descending.

QUITS THE BAVARIAN SERVICE-RESIDENCE IN LONDON AND PARIS-DEATH AND CHARACTER.

To return to Count Rumford's life. After some stay in Great Britain, he returned to Munich in 1796, accompanied by his daughter, who had come over from America at his request, her mother having died in 1792. What were Count Rumford's relations with America during the long interval of his absence from it, we have no means of ascertaining; as far as can be inferred, however, he seems to have maintained little correspondence with his former friends in the United States till after his wife's death; and one cannot help remarking the unpleasing circumstance, that while on one side of the Atlantic the husband was enjoying an honourable position, and filling a large space in the public eye, the wife and daughter continued during the life of the former to reside on the other.

Rumford, on his return to Munich, was occupied in very important affairs. The advance of the French republican army under Moreau obliged the elector to quit the capital, leaving a Council of Regency, with Rumford at its head. Rumford succeeded in the arduous task of freeing Bavaria from the invasion, and his conduct on this occasion increased his reputation with the elector and with the people. Among other tokens of the elector's gratitude for his services, he

was permitted to settle one-half of the pension which he enjoyed on his daughter, to be paid during her lifetime. In 1798, the elector, partly with a view to gratify him with an honour which he knew he desired, and partly to afford him another opportunity of relaxation for the improvement of his health, appointed him his ambassador at the court of Great Britain. On arriving in London, however, Rumford found, that in consequence of the English legal fiction, by which a born subject of the country is declared incapable of ever alienating his allegiance, he could not be received as the Bavarian ambassador. Mortified as he must have been by this circumstance, and still more deeply grieved by the loss of his friend and patron, the Elector Charles Theodore, who died in 1799, Rumford contemplated returning to spend the remainder of his life in the land of his birth. In compliance with a formal invitation which he received from the United States government, he was making preparations for his return, and had written to a friend to secure a cottage in the vicinity of Boston, as 'a quiet little retreat,' when he was led to change his design, and remain in London, in the society of which he occupied a conspicuous place. During several years, a great part of Count Rumford's time was devoted to the interests of the Royal Institution, of which indeed he may be considered the founder. The objects of this institution, now one of the recognised scientific establishments of the world, and which can boast of having given employment to such men as Young, Davy, Brande, and Faraday, were 'to diffuse the knowledge and facilitate the general introduction of useful mechanical inventions and improvements, and to teach, by courses of philosophical lectures and experiments, the application of science to the useful purposes of life. Such an institution was precisely the one which Rumford was qualified to superintend; and in its early history, the influence of his peculiar habits of thought is discernible in the choice of subjects for investigation by the members. Subsequently, the institution assumed the high scientific character which it yet holds.

In 1802, Count Rumford left England, and spent some time in travel. Revisiting Munich, he found the workhouse which he had planned, and which had been instrumental in producing so much good, abolished, and the new elector, Maximilian, friendly indeed, but indisposed to follow the footsteps of his predecessor. Accordingly, after assisting in modelling a Bavarian Academy of Sciences, he took farewell of his adopted country, and went to reside in Paris, retaining an income of about £1200 from the Bavarian court. At the same time his daughter returned to America, her father having abandoned his intention of returning along with her. In Paris, Count Rumford appears at first to have gained that good-will and esteem which had attended him so remarkably during his previous life; and not long after he began his residence there, he contracted a second marriage with the widow of the celebrated Lavoisier, put