In nature the realms of space, on the probable assumption that the interstellar medium is perfectly transparent and diathermanous, must, as was pointed out by W. J. Macquorn Rankine, be incapable of acquiring any temperature, and must therefore be at the absolute zero. That, however, is not to say that if a suitable thermometer could be projected into space it would give a reading of -273°. On the contrary, not being a transparent and diathermanous body, it would absorb radiation from the sun and other stars, and would thus become warmed. Professor J. H. Poynting (“Radiation in the Solar System,” Phil. Trans., A, 1903, 202, p. 525) showed that as regards bodies in the solar system the effects of radiation from the stars are negligible, and calculated that by solar radiation alone a small absorbing sphere at the distance of Mercury from the sun would have its temperature raised to 483° Abs. (210° C), at the distance of Venus to 358° Abs. (85° C), of the earth to 300° Abs. (27° C), of Mars to 243° Abs. (-30° C), and of Neptune to only 54° Abs. (-219° C.). The French physicists of the early part of the 19th century held a different view, and rejected the hypothesis of the absolute cold of space. Fourier, for instance, postulated a fundamental temperature of space as necessary for the explanation of the heat-effects observed on the surface of the earth, and estimated that in the interplanetary regions it was little less than that of the terrestrial poles and below the freezing-point of mercury, though it was different in other parts of space (Ann. chim. phys., 1824, 27, pp. 141, 150). C. S. M. Pouillet, again, calculated the temperature of interplanetary space as -142° C. (Comptes rendus, 1838, 7, p. 61), and Sir John Herschel as -150° (Ency. Brit., 8th ed., art. “Meteorology,” p. 643).
To attain the absolute zero in the laboratory, that is, to deprive a substance entirely of its heat, is a thermodynamical impossibility, and the most that the physicist can hope for is an indefinitely close approach to that point. The lowest steady temperature obtainable by the exhaustion of liquid hydrogen is about -262° C. (11° Abs.), and the liquefaction of helium by Professor Kamerlingh Onnes in 1908 yielded a liquid having a boiling-point of about 4.3° Abs., which on exhaustion must bring us to within about 2½ degrees of the absolute zero. (See [Liquid Gases].)
For a “cold,” in the medical sense, see [Catarrh] and [Respiratory System]: Pathology.
COLDEN, CADWALLADER (1688-1776), American physician and colonial official, was born at Duns, Scotland, on the 17th of February 1688. He graduated at the university of Edinburgh in 1705, spent three years in London in the study of medicine, and emigrated to America in 1708. After practising medicine for ten years in Philadelphia, he was invited to settle in New York by Governor Hunter, and in 1718 was appointed the first surveyor-general of the colony. Becoming a member of the provincial council in 1720, he served for many years as its president, and from 1761 until his death was lieutenant-governor; for a considerable part of the time, during the interim between the appointment of governors, he was acting-governor. About 1755 he retired from medical practice. As early as 1729 he had built a country house called Coldengham on the line between Ulster and Orange counties, where he spent much of his time until 1761. Aristocratic and extremely conservative, he had a violent distrust of popular government and a strong aversion to the popular party in New York. Naturally he came into frequent conflict with the growing sentiment in the colony in opposition to royal taxation. He was acting-governor when in 1765 the stamped paper to be used under the Stamp Act arrived in the port of New York; a mob burned him in effigy in his own coach in Bowling Green, in sight of the enraged acting-governor and of General Gage; and Colden was compelled to surrender the stamps to the city council, by whom they were locked up in the city hall until all attempts to enforce the new law were abandoned. Subsequently Colden secured the suspension of the provincial assembly by an act of parliament. He understood, however, the real temper of the patriot party, and in 1775, when the outbreak of hostilities seamed inevitable, he strongly advised the ministry to act with caution and to concede some of the colonists’ demands. When the war began, he retired to his Long Island country seat, where he died on the 28th of September 1776. Colden was widely known among scientists and men of letters in England and America. He was a life-long student of botany, and was the first to introduce in America the classification system of Linnaeus, who gave the name “Coldenia” to a newly recognized genus. He was an intimate friend of Benjamin Franklin. He wrote several medical works of importance in their day, the most noteworthy being A Treatise on Wounds and Fevers (1765); he also wrote The History of the Five Indian Nations depending on the Province of New York (1727, reprinted 1866 and 1905), and an elaborate work on The Principles of Action in Matter (1751) which, with his Introduction to the Study of Physics (c. 1756), his Enquiry into the Principles of Vital Motion (1766), and his Reflections (c. 1770), mark him as the first of American materialists and one of the ablest material philosophers of his day. I. Woodbridge Riley, in American Philosophy (New York, 1907), made the first critical study of Colden’s philosophy, and said of it that it combined “Newtonian mechanics with the ancient hylozoistic doctrine ...” and “ultimately reached a kind of dynamic panpsychism, substance being conceived as a self-acting and universally diffused principle, whose essence is power and force.”
See Alice M. Keys, Cadwallader Colden, A Representative 18th Century Official (New York, 1906), a Columbia University doctoral dissertation; J. G. Mumford, Narrative of Medicine in America (New York, 1903); and Asa Gray, “Selections from the Scientific Correspondence of Cadwallader Colden” in American Journal of Science, vol. 44, 1843.
His grandson, Cadwallader David Colden (1769-1834), lawyer and politician, was educated in London, but returned in 1785 to New York, where he attained great distinction at the bar. He was a colonel of volunteers during the war of 1812, and from 1818 to 1821 was the successor of Jacob Radcliff as mayor of New York City. He was a member of the state assembly (1818) and the state senate (1825-1827), and did much to secure the construction of the Erie Canal and the organization of the state public school system; and in 1821-1823 he was a representative in Congress. He wrote a Life of Robert Fulton (1817) and a Memoir of the Celebration of the Completion of the New York Canals (1825).
COLD HARBOR, Old and New, two localities in Hanover county, Virginia, U.S.A., 10 m. N.E. of Richmond. They were the scenes of a succession of battles, on May 31-June 12, 1864, between the Union forces under command of General U. S. Grant and the Confederates under General R. E. Lee, who held a strongly entrenched line at New Cold Harbor. The main Union attack on June 3 was delivered by the II. (Hancock), VI. (Wright), and XVIII. (W. F. Smith) corps, and was brought to a standstill in eight minutes. An order from army headquarters to renew the attack was ignored by the officers and men at the front, who realized fully the strength of the hostile position. These troops lost as many as 5,000 men in an hour’s fighting, the greater part in the few minutes of the actual assault. In the constant fighting of 31st of May to 12th of June on this ground Grant lost 14,000 men. (See [Wilderness] and [American Civil War].)