NOTE 1.-GAS.

GAS is an aeriform fluid, composed of two parts: 1. The particular substance that is converted into gas, by heat or caloric; 2. The Caloric, which, by its chemical combination with the basis, constitutes a gas or permanently elastic fluid, capable of existing in an aeriform state, under the pressure, and at the temperature of the atmosphere. To form a gas, or permanently elastic fluid, a chemical combination must take place between the caloric and the substance, at the time of its being converted into a gaseous state. This combination cannot be destroyed, except by the aid of some chemical agent that has a stronger affinity for either of the constituents of the gas.

Vapour is an elastic fluid, bearing a strong resemblance to a gas; but vapour is nothing more than the solution, or medicinal division, of any substance whatever in caloric. Caloric in vapour is only latent, and not chemically combined: its union is so slight, as to be separated by simply lowering the temperature.

NOTE 2.-CARBON.

Carbon, or Charcoal, forms a considerable part of the solid matter of all organized bodies; but it is most abundant in the vegetable creation; and chiefly obtained from wood, when the oil and water, (which are the other constituents of vegetable matter) are evaporated; the black porous brittle substance that then remains is called charcoal. Charcoal, or artificial carbon is properly called an Oxyd of Carbon. All carbon is not black-many substances consisting chiefly of carbon, are remarkably white; cotton, for instance, is almost wholly carbon. In the diamond alone, carbon exists in its purest and most perfect state. We are ignorant of the means which nature employs to bring it to that state; it may probly be the work of ages, to purify, arrange and unite the particles of carbon in the form of a diamond.

Oxygen, when in a state of combination with other substances loses, in almost every instance, its respirable properties, and when combined with carbon, is not only unfit for respiration, but extremely deleterious if taken into the lungs. This accounts for the unwholesome fumes of burning charcoal. By the combustion of charcoal, it gradually combines with the oxygen of the atmosphere, for which it has a great attraction, and flies off in a gaseous state, called carbonic acid gas, or fixed air.

This carbonic acid gas produces many unhapppy accidents at the opening of cellars, in places where wine, cider, or beer are suffered to ferment. The famous Lake Avernus, in Italy, by modern Italians called Lago di Tripergola and which Virgil makes the entrance of hell, exhaled so large a quantity of carbonic acid gas, that birds could not fly over it with impunity.

Carbon in a state of gas, is also found at the celebrated Grotto del Cani, near Naples. History informs us that criminals who were made to descend into the grotto were immediately stifled. Water can absorb this gas, as is seen in many of our mineral waters, to which it gives a slight acid taste; and, although prejudicial to respiration, it is sometimes found to be beneficial to the stomach.

NOTE 3.-UMBELLIFEROUS PLANTS.

Umbelliferous plants (from the Latin umbello, and fero to bear,) are those plants producing the inflorescence called an umbel. A particular mode of flowering, which consists of a number of flower-stalks or rays, nearly equal in length, spreading from a common centre, their summits forming a level, convex, or even globose surface, as in hemlock; more rarely a concave one, as the carrot. It is simple or compound; in the latter, each peduncle bears another little umbel, umbellet, or umbellicle.

Umbel, is sometimes called a rundle, from its roundness.

Ir may not be deemed out of place to give a brief sketch of the life of the illustrious author of systematized botany, which has been so nearly perfected by his indefatigable labours.

CHARLES LINNEUS (afterwards Von Linné) was born at Râshult, in Sweden, in 1707. His father Nicholas Linnæus, was minister of the parish of Stenbrohult, to which the hamlet of Râshult belongs. He was a great admirer of the vegetable productions of Nature, and adorned the environs of his rural mansion with the native plants of the neighbouring fields. Young Linnæus caught his parent's enthusiasm, and early imbibed the same taste, with such warmth, that he was never able to bend his mind, with any great success, to other pursuits. He relates of himself, that, when yet scarcely four years old, he heard his father descant, to a rural party, on the distinctive qualities of some particular plants, culled from the flowery bank on which they were seated, and that this first botanical lecture was ever after remembered as an epoch in his scientific life.

His father designed him for the church; but he had no particular relish for the profession, or its preparatory studies, being a very inapt scholar in the study of languages, either ancient or modern. In his diary, written in later years, he confesses a peculiar inaptitude, and rather a blameable indifference, for the learning of languages: declaring, that in all his travels, he learned neither English, French, German, Laplandish, nor even Dutch, though he stayed in Holland three whole years. Nevertheless, he found his way every where well and happily.'

At the age of nineteen, his tutors, like the sapient instructors of Newton at Cambridge, gave him up as a hopeles dunce; advising that he should be apprenticed to some mechanical trade. Fortunately for him, and for the world, one of the lecturers on Natural Philosophy, Dr. Rothmann, having observed his passion for the study of Nature, and his practical observation, recommended to his disappointed parent to turn his attention to the study of medicine; which advice was adopted, and he, afterwards, became a practising physician of some eminence. The amiable professor who had thus

interested himself for him, gave him private instruction in physiology. He first suggested to Linnæus the true principles upon which botany ought to be studied— founded on the parts of fructification, and put the system of Tournefort into his hands, whose orders are distinguished by the fruit. Its very imperfections proved useful, in prompting him to attempt something more complete thereafter.

From that time Linnæus devoted all his leisure to his favourite study. In early life he had to struggle with many difficulties; being so poor, as frequently to depend upon chance for a meal; and without the means of paying for a patch upon his shoes, which he sometimes endeavoured to repair himself, by the aid of folded paper. But merit and industry will always find their reward, and rise proudly superior to all impediments. The lustre of his abilities soon drew the attention of some of the most learned men in Europe, who encouraged and patronized him. He was, after a time, elected a member of various scientific academies throughout Europe; and, in his own country, made Secretary of the Upsal Academy, the only one then in Sweden; besides many other distinguished marks of the high estimation in which he was held in his native country, and in the literary world. His studies were not wholly confined to botany, but extended to other branches of natural history, as may be seen by the publication of his many scientific and varied works.

In the spring of 1732, he received from the Academy of Sciences at Upsal, an appointment to travel through Lapland, under the royal authority, and at the expense of the Academy. He was but slenderly provided with Laggage, travelled generally on horseback, but visited the Lapland Alps on foot-descending to the coast of Norway, he returned by Tornea, &c. to Upsal, by the 10th of October, having performed a journey of near 4000 English miles.

When in Lapland, he gathered at Lyksele, May 29th, 1732, an elegant and singular little plant, formerly known to botanists as the Campanula Serpyllifolia. Linnæus, by his study of vegetables on the only certain principles, the structure of their parts of fructification, soon found

this to constitute a new genus; but he reserved the idea in his own breast, till such time as his discoveries and publications had entitled him to botanical commemoration: and his friend Grovinius, in due time, undertook to make this genus known to the world under the name of Linnæa-it having been chosen by himself for this purpose.

In the course of his tour, having learned the art of assaying metals, he in the following year gave a private course of lectures on this subject, which had never before been taught at Upsal.

The arts of his rival Rosen having disappointed him of his anticipated medical advancement in the college at Lund, and, by his intrigues put a stop to all private medical lectures in the University of Upsal, thus depriving Linnæus of his only present means of subsistence, our indefatigable naturalist directed his energies into another channel; in furtherance of his study of mineralogy, he visited the mines of Sweden, and, at the close of the year 1733, he gave a course of lectures at Fahlun, on the art of assaying. Here he first became acquainted with Browallius (chaplain to the governor of the province of Dalecarlia, afterwards bishop of Abo) who advised him to take his doctor's degrees, in order to pursue the practice of medicine, in which he had already acquired some celebrity while at Fahlun.

In pursuance of this advice, Linnæus, having amassed the sum of fifteen pounds sterling, now commenced his travels, with a view of obtaining his degree at the cheapest University he could find, and, at the same time, seeing something more of the literary world. He spent five years in visiting the principal countries of Europe; his merit raised him up patrons and friends wherever he was known; through many difficulties, it is true, did he have to work his way, but still he went onward, supported by the native energy of his character, gaining information at every step, and extending his own fame. He tells us himself, he would perhaps never have returned to his own country, had he not been in love;' but hearing that he had a powerful rival in the affections of her to whom he had plighted his faith, he suddenly returned to Sweden, and, after a time, having acquired such a degree of prosperity as to induce the father of his betrothed to consent to their union, he was married June 26, 1739.

How distant oft the things we dote on most,
From that for which we dote, felicity!

The consummation of his ardent aspirations for the last five years of his life, brought with it no access either of happiness or prosperity. This idol of his heart is represented as altogether unworthy; and of a

kindred spirit with the unnatural mother of the unfortunate poet Savage, displaying the same hatred of her only son, and persecuting him by every means within her power, during the life of her husband, who was made miserable by her misconduct and petty tyranny, and, after his death, still pouring out the dregs of her wrath upon the admirable and sensitive being who naturally looked to her for support and comfort.

But let us turn from so disgusting and painful a theme, to bestow a double portion of admiration upon that being, who, amidst all these chilling blights to his happiness, still laboured with untiring zeal in the cause of literature.

About the year 1751, the queen of Sweden, Louisa Ulrica, sister to the great Frederick of Prussia, having a taste for natural history, which her royal consort, king Adolphus Frederick, also patronized, showed much favour to Linnæus, and employed him in arranging her collection of insects and shells, at her country palace of Drotningholm, or Ulricksdahl, and he was frequently honoured with the company and conversation of their majesties, during his attendance there. The queen also interested herself in the education of his son, and was altogether gracious and obliging in all that concerned him, promoting his wishes and his interest, whenever opportunity offered. She took so much pleasure in the conversation of her distinguished naturalist, that she allowed him his habitual indulgence of smoking, even in her royal apartments, that he might continue his labours with the more satisfaction to himself. Nor were his services accepted without suitable returns of royal munificence.

In 1753, he received, from the hand of his sovereign, the order of the Polar Star; an honour which had never before been conferred for literary merit. A still more remarkable, if not more grateful compliment, was paid him, not long after, by the king of Spain; who invited him to settle at Madrid, with the offer of nobility, the free exercise of his religion, and a splendid botanical appointment. This was handsomely declined by Linnæus, who declared, that if he had any merits, they were due to his own country. The patriotic moderation received its just reward in November 1756, when he was raised to the rank of Swedish nobility, and took the name of Von Linné.

As the habits of Linnæus were temperate and regular, he retained his health and vigour in tolerable perfection, notwithstanding the immense labours of his mind, till beyond his sixtieth year; when his memory began, in some degree, to fail him. In 1774, at the age of sixty-seven, an attack of apoplexy greatly impaired his constitution. Two years afterwards, he had a second attack, which rendered him paralytic on the right side,

and materially affected his faculties. He died of a different complaint, in 1778, aged seventy-one. His sovereign, Gustavus III. commanded a medal to be struck, expressive of the public loss his country had sustained in him; and honoured the Academy of Science, at Stockholm, with his presence, when the eulogy of this ornament to his country was pronounced there by his intimate friend Black. A still higher compliment was paid to his memory by the king, in a speech from the throne, in which he did justice to the splendid talents and acquirements of his illustrious subject, and testified his royal sympathy with the sorrow of a whole nation, in their irreparable loss. Nor was this sorrow limited to the narrow bounds of his native soil: the whole literary world, with whom he had become intimately connected, and to whom he was endeared, felt

the shock of such a bereavement. Eulogies were pronounced in the several scientific institutions of which he was a member. In his own country, there was a general mourning proclaimed at Upsal-his remains were deposited in a vault near the west end of the cathedral of the University, where a monument of Swedish porphyry was erected by his pupils. His obsequies were performed in the most respectful manner by the whole University, the pall being supported by sixteen doctors of physic, all of whom had been his pupils.

Five years after this, the remains of his only son (then in his forty-second year, successor to his father in his botanical professorship, which he supported with ability) were laid by the side of the parent, the family coat of arms broken over them, and their mingled ashes strewed with flowers.