Classification essays rank the groups of objects according to a common standard. For example, popular inventions may be classified according to their significance to the humankind.
Classification is a convenient method of arranging data and simplifying complex notions.
When you select a topic, do not forget about the length of your paper. Choose the topic you will be able to cover in your essay, do not write about something global or general.
Consider these examples:
- Evaluate the best to worst methods of upbringing.
- Rate the films according to their influence on people.
- Classify careers according to the opportunities they offer.
You should point out the common classifying principle for the group you are writing about. It will become the thesis of your essay.
It is important for you to use clear method of classification in your essay, especially when you are dealing with subjective categories such as "quality" or "benefit". Make sure you explain what you mean by this term.
To organize a classification essay, the writer should:
- categorize each group.
- describe or define each category. List down the general characteristics and discuss them.
- provide enough illustrative examples. An example should be a typical representative of the group.
- point out similarities or differences of each category, using comparison-contrast techniques.
|SKETCH OF SAMUEL LATHAM MITCHILL.|
THE name and fame of Dr. Samuel L. Mitchill have, in the absence of a complete biography, become to a considerable extent a tradition, known to few except students; yet, during the first quarter of this century, he was one of the most conspicuous figures in the literary and scientific life of the United States. He is called by Dr. J. W. Francis "the Nestor of American science," and "the pioneer philosopher in the promotion of natural science and medicine in America." He was a man of various attainments, and proved himself at home in many fields—in medicine, science, letters, politics, and social life.
Samuel Latham Mitchill was born in Hempstead, Long Island, August 20, 1769, and died in the city of New York, September 7, 1831. He was the third son of Robert Mitchill, an industrious farmer and member of the Society of Friends, and was remarkable for his habits of observation and reflection. His father seems to have taken less interest in his early instruction than his maternal uncle, Dr. Samuel Latham, of North Hempstead, who assisted him to obtain a good classical education. He afterward studied medicine with Dr. Latham; then with Dr. Samuel Bard, of New York; and in 1783 went to complete his studies in the University of Edinburgh, whence he was graduated in 1786. He enjoyed here rare advantages of intellectual society, and had among his contemporaries at the university such illustrious men as Sir James Mackintosh and Thomas Addis Emmet, Dr. Caspar Wistar, Richard S. Kissam, the surgeon; and William Hammersley, afterward a professor in Columbia College. After graduation, and before returning home, he made a pedestrian tour through a part of England. In 1787, after his return to America, he visited Saratoga Springs while it was surrounded by the forest, and ascertained experimentally that the gas extricated from the water was "fixed air, with the power to extinguish flame, destroy the life of breathing animals, etc." He is found in 1788 recording his walking with congenial companions "in the very grand procession for celebrating the adoption of the Constitution of the United States." He began the study of law with the Hon. Robert Yates, Chief Justice of the State of New York, and was shortly afterward appointed one of the commissioners to treat with the Five Nations for the cession of the "Great Western District" to the State of New York. He attended the council at Fort Stanwix, witnessed the deed, and received names from the Oneidas and Onondagas.
In 1790 Dr. Mitchill was chosen a representative from Queens County in the New York Legislature. In the next year he exerted himself to form the North Hempstead Library Association and Library. In 1792 he was appointed Professor of Chemistry, Natural History, and Philosophy in Columbia College, where, while dissenting from some of the principles of the French chemist, he introduced, for the first time in the United States, the chemical nomenclature devised by Lavoisier. His dissent from Lavoisier led to a controversy with Dr. Priestley, at the end of which the two disputants found themselves on a footing of mutual esteem and warm personal friendship. He records himself in 1794 as having exhibited at full length, in a printed essay, the actual state of learning in Columbia College. At about this time, too, he was co-operating with Chancellor Livingston and Simeon De Witt in the establishment of the Society for the Promotion of Agriculture, Manufactures, and the Useful Arts, before which he delivered his first public address. Having executed a commission from this society for that work, he made a detailed report, in 1796, of geological and mineralogical observations on the banks of the Hudson, for coal, etc.—a performance which, he mentions, was respectfully quoted by Count Volney. This was the first work of the kind undertaken in the United States, and the report helped to secure a wide European as well as American reputation for the author. Referring to it, Dr. J. W. Francis says, "He may fairly be pronounced the pioneer investigator of geological science among us, preceding McClure by several years." The report was published in the Medical Repository, a quarterly magazine begun in 1797 by Dr. Mitchill, with Drs. Edward Miller and Elihu H. Smith, and continued by Dr. Mitchill for more than sixteen years. After his marriage, in 1799, to Mrs. Catharine Cock, which brought him the enjoyment of an ample fortune, Dr. Mitchill was able to devote himself entirely to scientific and public occupations. Among the scientific works with which he accredits himself during the few years succeeding this event is the publication of a chart of chemical nomenclature, with an explanatory memoir, in which he contended that metals in their malleable and ductile state are compounds of a base with hydrogen (phlogiston), as in their calciform state they consist of a base with oxygen; and that in several there is an intermediate condition in which there is no union either with hydrogen or oxygen. And he extended the same doctrine to the greater part of inflammable bodies. In 1802 he records a correspondence with Albert Gallatin, Secretary of the Treasury, on a project for illuminating the lighthouses of the United States with inflammable air. In 1806 he wrote the introduction to the American edition of Assalini's Observations on the Plague, Dysentery, and Ophthalmy of Egypt; and in the ensuing winter translated from the Latin Lancisi's book on the noxious exhalations of marshes at Washington—a work which, was afterward printed in the Medical Repository. As a member of the Legislature, he supported, in the face of ridicule and opposition, the act of 1798 giving Livingston and Fulton the exclusive right to navigate the waters of New York by steam. He performed, with Fulton, in August, 1807, the first voyage in a steamboat. He was again chosen to the Assembly in 1797 as one of the representatives from the city and county of New York for a term of service which he marked as distinguished by his introduction of a motion relative to the sixth commandment, requiring citizens to-labor on the six days as well as to refrain from labor on the seventh day. In 1801 he was elected to the national House of Representatives, as member from the district consisting of the counties of Kings and Richmond and the city and county of New York. He was appointed to the Senate in 1804, to fill the vacancy caused by the resignation of John Armstrong, and after the expiration of his term there, in 1809, served in the House again till 1813. A bright picture of his life in Washington is given in the letters written by him to his wife during his term of service, a selection from which was published in Harper's Magazine in 1879. They are full of the life of the politics and the society of the capital, and the telling of the incidents is made more attractive by the writer's always lively humor.
The lines of Dr. Mitchill's work in Congress are indicated by various notes in his letters and in the record which he has left of Memorable Events and Occurrences in his life. During his first term he was a member of committees of the House on Commerce and Manufactures, the Naturalization Laws, the protection of American seamen and commerce against the Tripolitan corsairs, Naval Affairs, memorials concerning perpetual motion, Patent Rights, the Mint, and French spoliations. He labored in the Senate for the adoption of improved quarantine laws, "and was strenuous," says Dr. Francis, "to lessen the duty on the importation of rags, in order to render the manufacture of paper cheaper, the better to aid the diffusion of knowledge by printing." In December, 1811, he brought up for adoption by the House of Representatives a report favorable to the "nascent nations" of Spanish America, and "full of good wishes toward them in their exertions to become free and independent." In connection with the War of 1812 he acted as a commissioner under the Navy Department in constructing a floating battery or heavy vessel of war, to defend the sea-coast and harbors of the United States; and in 1814 he was found laboring jointly with his patriotic neighbors, "with mattock and shovel, in the trenches for several days, to erect fortifications against the enemy."
National and social matters did not absorb Dr. Mitchill's attention in Washington to the exclusion of his interest in scientific inquiries. Curious speculations and remarks appear in his letters about phenomena which came under his observation. In one letter, Dr. Mitchill wishes his wife to inform him exactly at what hour a certain storm began. "I wish to know" he said, "exactly when the storm began in New York, as it is connected with other facts tending to a theory of the atmospheric motions in winter." Another letter, forwarding a specimen of the Mitchella repens, explains why no plant had been named after him. Prof. Willdenow, of Berlin, had intended to give his name to some plant, but found it already appropriated by this partridge-berry, which was named by Linnæus in honor of John Mitchell, of Virginia. He was more fortunate, according to Dr. Francis, in the matter of fish. "He was the delight," says this biographer, "of a meeting of naturalists. The seed he sowed gave origin and growth to a mighty crop of those disciples of natural science. He was emphatically our great living ichthyologist. The fishermen and fish-mongers were perpetually bringing him new specimens. They adopted his name for our excellent fish, the striped bass, and designated it the Perca Mitchilli."
He writes concerning a conversation he had with Captain Lewis, the explorer, about the burning plains up the Missouri, where the burning strata of coal underlying the plains produced such intense heat as to form lava, slag, and pumice-stone by the same process that forms those volcanic substances in the burning mountains of other countries. December 30, 1807, he congratulates his wife on the account in one of her letters of the meteoric stones that fell to the earth in Connecticut, which arrived at a most convenient time, having preceded all the letters to the Connecticut delegation, and even outrun the newspapers. Dr. Mitchill also during this period visited Upper Canada, and described the mineralogy of Niagara Falls; wrote a history of West Point and the Military Academy; and visited Harper's Ferry and described the geology and scenery of that spot, which had been eulogized for its sublimity by Jefferson' in his Notes on Virginia. Dr. Mitchill retired from his professorship in Columbia College on his election to Congress, in 1801. In 1807, when the College of Physicians and Surgeons of the City of New York was organized, he was chosen its first Professor of Chemistry, but declined the position, preferring his public duties. In 1808, however, he accepted a professorship of Natural History; and in 1820, on the reorganization of the faculty, became Professor of Botany and Materia Medica. Difficulties occurred with the Board of Trustees in 1828, and the whole faculty of the college resigned. Among other works for the advancement of science and learning mentioned in his record are his action with Drs. Hosack and Hugh Williamson in laying the foundation of a Literary and Philosophical Society in New York, in 1815; the reading to the society of a narrative of the earthquakes of the United States and in foreign parts, during 1811, 1812, and 1813; co-operation in a petition to the Common Council of New York for the grant of the building in the North Park for the purposes of Literature, Science, and Arts; the delivery, in connection with a curious case by which the town was stirred, of a public lecture on the Somnium, or dream, as a state different both from wakefulness and sleep; an excursion with friends to the region watered by the Wallkill, where the party disinterred a mammoth; participation in an excursion to the Neversink Hills, near Sandy Hook, where a dangerous mistake in their altitude, which had been supposed to be six hundred feet, was corrected, and the real height was found to be only half as great, or three hundred feet; acting as vice-president of the District Convention which met at Philadelphia for preparing a National Pharmacopœia; and co-operation with Samuel Wood and-Garrett K. Lawrence in recommending the willow-leaved meadow-sweet (Spiræa salicifolia) "as an admirable article for refreshment and health, and as a substitute for the tea of China." A description and classification of one hundred and sixty-six species of fish, chiefly found in the fresh and salt waters adjacent to the city of New York, which he offered to the Literary and Philosophical Society at one of its earlier meetings, was the nucleus of what is regarded as his chief work. He mentions in his record more than forty additional species described in Bigelow and Holly's Magazine, and several more in the Journal of the Philadelphia Academy of Sciences. An elaborate History by him of the Botanical Writers of America is to be found in the collections of the New York Historical Society. Of his literary and scientific work as a whole, in fact, it is well said in the Cyclopædia of American Literature that' numerous papers by him are included in the Transactions of the many learned societies of Europe and America of which he was a member; and he was often called upon, at the anniversaries of the societies of his own city, to appear as their orator. "His multifarious productions are consequently scattered over a number of publications and collections of pamphlets, and are somewhat overshadowed by the reputation of the learned bodies with which they are connected. They have fallen, to some extent, into an unmerited oblivion." He had committed his manuscripts to his brother-in-law, the late Dr. Samuel Akerly, as the friend most competent to write his biography, and the work was begun, when the papers were destroyed by the burning of the house in which they were deposited. Had Dr. Akerly not been thus prevented from completing this work, and had he been able to present Dr. Mitchill's life and writings in substantial form, the subject of our sketch would doubtless have received the credit to which he was entitled, and have been made to appear as one of the most vigorous leaders of early American science.
The scientific items in Dr. Mitchill's record are continued with mention of the introductory lecture to the College of Physicians, etc., on the life and writings of their late president, Samuel Bard, 1821; a philosophical discourse in St. Stephen's Chapel, Bowery, to the class formed in that congregation for cultivating the natural and physical sciences, 1822; a discourse on the Life and Writings of Linnæus, at Prince's Botanical Gardens, Flushing, on the anniversary of the Swede's birthday in 1823; and the publication of a catalogue of the geological articles and organic remains which he presented to the museum of the Lyceum. In 1823 he appears as performing, after the Venetian example, on an invitation from Albany and a mission from New York, the ceremony of marrying the Lakes to the Ocean, at Albany, "on the day of the unprecedented gathering of the people to witness the scene of connecting the Western and Northern Canals with the Hudson"; and again, two years afterward, as a member of a committee for celebrating the completion of the Western Canal, when, in the vicinity of Sandy Hook, he pronounced an address "on the introduction of the Lady of the Lake to the estate of her spouse the Lord of the Ocean." This, according to Dr. Francis, was the proudest day of his life. He also acted on a committee, in 1824, to receive funds in aid of the efforts of the Greeks to achieve thenindependence.
Dr. Francis says, summing up his work, and quoting at least a part of the estimate from the book, Old New York, that "the universal praise which Dr. Mitchill enjoyed in almost every part of the globe where science is cultivated, during a long life, is demonstrative that his merits were of a high order. . . . His knowledge was diversified and extensive, if not profound. His first scientific paper was an essay on Evaporation. His mineralogical survey of New York, in 1797, gave Volney many hints; his analysis of the Saratoga waters enhanced the importance of those mineral springs. ... His ingenious theory of the doctrine of septon and septic acid gave origin to many papers and impulse to Sir Humphry Davy's vast discoveries; his doctrines on pestilence awakened inquiry from every class of observers throughout the Union; his expositions of a theory of the earth and solar system captivated minds of the highest qualities. His speculations on the phosphorescence of the waters of the ocean, on the fecundity of fish, on the decortication of fruit trees, on the anatomy and physiology of the shark, swelled the mystery of his diversified knowledge. . . . His researches on the ethnological characteristics of the red men of America betrayed the benevolence of his nature and his generous spirit. . . . He increased our knowledge of the vegetable materia medica of the United States, and wrote largely on the subject. . . . He largely seconded the views of Judge Peters on gypsum as a fertilizer. . . . His letters to Tilloch, of London, on the progress of his mind in the investigation of septic acid—oxygenated azote—is curious as a physiological document. . . . He was associated with Griscom, Eddy, Colden, Gerard, and Wood in the establishment of the Institution for the Deaf and Dumb; and, with Eddy and Hosack, may be classed with the first in this city, in respect to time, who held converse with the afflicted mute by means of signs."
It would be difficult, says an article in Harper's Magazine for April, 1879, for those who never saw Dr. Mitchill, "to conceive the deference paid to his learning and judgment. His knowledge of the physical sciences, his varied and intimate acquaintance with classical literature, both ancient and modern, his attainments in history and political science, his practical acquaintance with public affairs, and his remarkable affinity with the common and useful arts, caused him to be looked upon as a fountain of learning always ready to pour forth abundant streams of knowledge to every thirsty applicant. A witty friend once said of him, 'Tap the doctor at any time, he will flow.' Accordingly, the merits of all inventions, discoveries, projects, arts, sciences, literary subjects and schemes, new books and publications, professional cases, acts of charity or public spirit, and a multitude of other things, used to be submitted to his critical opinion. If he had not been one of the most polite and amiable of men, he could hardly have borne the demands thus made upon his time and patience." Dr. Francis relates that, being present at his funeral, he stayed till all but the sexton had gone, and then asked, unrecognized by him, whom he had just buried. "A great character," the man answered, "one who knew all things on the earth and in the waters of the great deep." Dr. Francis is also authority for the story that when the purchase of the Elgin Botanic Garden by the constituted authorities was argued at the Capitol, "he won the attention of the members by a speech of several hours' length, in which he gave a history of gardens and the necessity for them. . . . With his botanical Latinity occasionally interspersed, he probably appeared more learned than ever. Van Horne, a western member, was dumfounded at the Linnæan phraseology, and declared such knowledge to be too deep for human powers to fathom."
As described by Dr. Francis, Dr. Mitchill's appearance before his class in the instruction-room was that of an earnest instructor, ready to impart the stores of his accumulated wisdom for the benefit of his pupils, while his oral disquisitions were perpetually enlivened with novel and ingenious observations. Chemistry, which first engaged his capacious mind, was rendered the more captivating by his endeavors to improve the nomenclature of the French savants, and to render the science subservient to the useful purposes of agriculture, art, and hygiene. In treating of the materia medica he delighted to dwell on the riches of our native products for the art of healing, and he sustained an enormous correspondence throughout the land, in order to add to his own practical observations the experience of the competent, the better to prefer the claims of our indigenous products.
Many of Dr. Mitchill's scientific papers were published in the London Philosophical Magazine, New York Medical Repository, American Medical and Philosophical Register, New York Medical and Physical Journal, American Mineralogical Journal, and Transactions of the Philosophical Society of Philadelphia; and he supplied several other periodicals, both abroad and at home, with the results of his cogitations.
Dr. Mitchill was the author of a few verses, and of prose essays or addresses of an order of humorous trifling, much affected at the time, of which the lighter works of Irving and Paulding furnish the most conspicuous examples, and with which Halleck's verses are in sympathy. One of his favorite topics was a proposition to give a new name—Fredon, or Fredonia—to the United States, after which the people should be called Fredes or Fredonians, and their relations Fredish or Fredonian. The subject was taken up and discussed in the New York Historical Society, but has long since been forgotten.
His social and domestic character, according to the writer in Harper's Magazine, was unusually amiable and attractive, and marked by many amusing peculiarities. He had great fondness for young people, and a rare power of inspiring them with the love of knowledge. His home was pleasant and unpretending, "and the numerous celebrities who used to resort to his salon were entertained with cordial but simple hospitality." His house was a perfect museum of curiosities, and Mrs. Mitchill used to be troubled by the disorder they occasioned. As pertinent to this nuisance, the story of the ant-eater's skin was told.. At first the skin was an object of great interest. Then it became dingy and dusty, and was remanded to the garret. In two or three years more it became old and moth-eaten, and Mrs. Mitchill and the servant, not wishing to worry the doctor, had it secretly carried off and thrown into the street. Dr. Mitchill, taking his regular walk the next morning, came upon a group of boys curiously looking at some unusual object, which proved to be the ant-eater's skin. He joined them, and, after giving them a full scientific lecture on the ant-eater, said he had a skin like this one at home and would bo glad to have another—and bought it from them for fifty cents. No further attempts were made to get rid of it.