of Alfred Nachet, who in 1853, and subsequently in 1863, brought | partnership with the Zeiss firm (E. Abbe and C. Pulfrich), conforward two forms of binocular microscope. structed the first stereoscopic range-finder suitable for practical use. (O. HR.) BINOMIAL (from the Lat. bi-, bis, twice, and nomen, a name or term), in mathematics, a word first introduced by Robert Recorde (1557) to denote a quantity composed of the sum or difference to two terms; as a+b, a-b. The terms 'trinomial, quadrinomial, multinomial, &c., are applied to expressions composed similarly of three, four or many quantities. The earliest stages of the development of the binocular microscope had been always confined to those instruments with one objective, in the immediate neighbourhood of which the systems for dividing the pencil were placed. At a låter date attempts were made to separate the two halves of the objective by modifying the eye-piece; this led to the construction of stereoscopic eye-pieces, initiated by R. B. Tolles, E. Abbe and A. Prazmowski. Of special importance is the work of Abbe; although, as he himself has stated, his methods accidentally led to the Wenham system, he certainly was far above his predecessors in his theoretical treatment of the problem, and in the perspicuity and clearness of his explanation. To him is also due the re-establishment of the instruments, which Wenham had abandoned by reason of too great technical difficulties (fig. 8) The newest form of the binocular microscope is very similar to the oldest form in which two completely separated The binomial theorem is a celebrated theorem, originally due to Sir Isaac Newton, by which any power of a binomial can be expressed as a series. In its modern form the theorem, which is true for all values of n, is written as n.n-1.n-23-3...+a". The (x+a)" =x+nax”-1+" 1.2.3 reader is referred to the article ALGEBRA for the proof and applications of this theorem; here we shall only treat of the history of its discovery. 1.2 The original form of the theorem was first given in a letter, dated the 13th of June 1676, from Sir Isaac Newton to Henry Oldenburg for communication to Wilhelm G. Leibnitz, although Newton had discovered it some years previously. Newton • m there states that (p+pq) = p2 + aq+! m-n Simple micro tubes were employed. The inventor, H. S. Greenough, employs scope. FIG. 9. Binocular Instruments for Range-finding. For measuring purposes binocular telescopes with parallel axes are 2n m-2n "bg+. 3n cg... &c., where p+pq is the quantity whose power or root is required, p the first term of that quantity, and q the quotient of the rest the power, which may be a positive or negative divided by integer or a fraction, and a, b, c, &c., the several terms in order, e.g. a=p, b=maq, c= m-nbq, and so on. 2n In a second letter, dated the 24th of October 1676, to Oldenburg, Newton gave the train of reasoning by which he devised the theorem. ing the works of the celebrated Dr Wallis, and considering the series "In the beginning of my mathematical studies, when I was perusby the interpolation of which he exhibits the area of the circle and hyperbola (for instance, in this series of curves whose common base or axis is x, and the ordinates respectively (1-xx), (1−xx)1, (1−xx)3, (1 − xx)1, &c), I perceived that if the areas of the alternate curves, which are x, x-xx-xx2+}x3,x−}x3+8x-4x2, &c., could be interpolated, we should obtain the areas of the intermediate ones, the first of which (1-xx) is the area of the circle. Now in order to [do] this, it appeared that in all the series the first term was x; that the second terms x, x, x, &c., were in arithmetical progression; and consequently that the first two terms of all the series to be interpolated would be x-3 x-1x, &c. 3 tinued multiplication of the terms of this series-1x2 3 the only types employed. The measurement is effected by adjoining to the space or interval to be measured some means of measurement defined; for example, by a fixed scale which extends into the space, or by a movable point (Wandermarke). This instrument shows a transition to the stereoscope, inasmuch as them....And hence I found the required area of the circular segment _x3 __ x _ x2, &c. ... And in the same manner might be scale or means of measurement is not directly observed, but to be x- 3 5 7 to each eye a plane representation is offered, just as in the produced the interpolated areas of other curves; as also the stereoscope; the space to be measured, on the other hand, area of the hyperbola and the other alternates in this series is portrayed in exactly the same way as in the double telescope. (1+xx), (1+xx)3, (1+xx)3, &c. ... Having proceeded so far, I The method for superposing the two spaces on one another considered that the terms (1-xx), (1−xx)1, (1−xx)3, (1−xx)3, was deduced by Sir David Brewster in 1856, but he does not &c., that is 1, 1-x2, 1-2x2+x1, 1-3x2+3x-x, &c., might be appear to have dealt with the problem of range-finding. The them, and for this, nothing more was required than to omít interpolated in the same manner as the areas generated by problem was attacked in 1861 by A. Rollet; later, in 1866, the denominators 1, 3, 5, 7, &c., in the terms expressing the E. Mach published a promising idea, and finally-independently areas; that is, the coefficients of the terms of the quantity to of the researches of his predecessors-Hektor de Grousilliers, in be interpolated (1−xx)1 or (1−xx), or generally (1−xx)TM will be produced by the continued multiplication of this series | about. No biological generalization rests on a wider series of m m-2 m 3. &c." 2 4 The binomial theorem was thus discovered as a development of John Wallis's investigations in the method of interpolation. Newton gave no proof, and it was in the Ars Conjectandi (1713) that James Bernoulli's proof for positive integral values of the exponent was first published, although Bernoulli must have discovered it many years previously. A rigorous demonstration was wanting for many years, Leonhard Euler's proof for negative and fractional values being faulty, and was finally given by Niels Heinrik Abel. The multi- (or poly-) nomial theorem has for its object the expansion of any power of a multinomial and was discussed in 1697 by Abraham Demoivre (see COMBINATORIAL ANALYSIS). REFERENCES. For the history of the binomial theorem, see John Collins, Commercium Epistolicum (1712); S. P. Rigaud, The Correspondence of Scientific Men of the 17th Century (1841); M. Cantor, Geschichte der Mathematik (1894-1901). BINTURONG (Arctictis binturong), the single species of the viverrine genus Arctictis, ranging from Nepal through the Malay Peninsula to Sumatra and Java. This animal, also called the bear-cat, is allied to the palm-civets, or paradoxures, but differs from the rest of the family (Viverridae) by its tufted ears and long, bushy, prehensile tail, which is thick at the root and almost equals in length the head and body together (from 28 to 33 inches). The fur is long and coarse, of a dull black hue with a grey wash on the head and fore-limbs. In habits the binturong is nocturnal and arboreal, inhabiting forests, and living on small vertebrates, worms, insects and fruits. It is said to be naturally fierce, but when taken young is easily tamed and becomes gentle and playful. BINYON, LAURENCE (1869- ), English poet, born at Lancaster on the 10th of August 1869, was educated at St Paul's school, London, and Trinity College, Oxford, where he won the Newdigate prize in 1890 for his Persephone. He entered the department of printed books at the British Museum in 1893, and was transferred to the department of prints and drawings in 1895, the Catalogue of English Drawings in the British Museum (1898, &c.) being by him. As a poet he is represented by Lyric Poems (1894), Poems (Oxford, 1895), London Visions (2 vols., 1895-1898), The Praise of Life (1896), Porphyrion and other Poems (1898), Odes (1900), The Death of Adam (1903), Penthesilea (1905), Dream come true (1905), Paris and Oenone (1906), a one-act tragedy, and Attila, a poetical drama (1907); as an art critic by monographs on the 17th-century Dutch etchers, on John Crome and John Sell Cotman, contributed to the Portfolio, &c. In 1906 he published the first volume of a series of reproductions from William Blake, with a critical introduction. See also R. A. Streatfeild, Two Poets of the New Century (1901), and W. Archer, Pocts of the Younger Generation (1902). BIO-BIO, a river of southern Chile, rising in the Pino Hachado pass across the Andes, 38° 45′ S. lat., and flowing in a general north-westerly direction to the Pacific at Concepción, where it is 2 m. wide and forms an excellent harbour. It has a total length of about 225 m., nearly one half of which is navigable. BIO-BIO, an inland province of southern Chile, bounded N., W. and S. respectively by the provinces of Concepción, Arauco and Malleco, and E. by Argentina. It has an area of 5246 sq. m. of well-wooded and mountainous country, and exports timber to a large extent. The great trunk railway from Santiago S. to Puerto Montt crosses the western part of the province and also connects it with the port of Concepción. The capital, Los Angeles (est. pop. 7777 in 1902) lies 15 m. E. of this railway and is connected with it by a branch line. BIOGENESIS (from the Gr. Bios, life, and yéveous, generation, birth), a biological term for the theory according to which each living organism, however simple, arises by a process of budding, fission, spore-formation of sexual reproduction from a parent organism. Under the heading of ABIOGENESIS (q.v.) is discussed the series of steps by which the modern acceptance of biogenesis and rejection of abiogenesis has been brought observations, or has been subjected to a more critical scrutiny than that every living organism has come into existence from a living portion or portions of a pre-existing organism. In the articles REPRODUCTION and HEREDITY the details of the relations between parent and offspring are discussed. There remains for treatment here a curious collateral issue of the theory. It is within common observation that parent and offspring are alike: that the new organism resembles that from which it has come into existence: in fine, biogenesis is homogenesis. Every organism takes origin from a parent organism of the same kind. The conception of homogenesis, however, does not imply an absolute similarity between parent and organism. In the first place, the normal life-cycle of plants and animals exhibits what is known as alternation of generations, so that any individual in the chain may resemble its grand-parent and its grand-child, and differ markedly from its parent and child. Next, any organism may pass through a series of free-living larval stages, so that the new organism at first resembles its parent only very remotely, corresponding to an early stage in the life-history of that parent. (See EMBRYOLOGY, LARVAL FORMS and REPRODUCTION.) Finally, the conception of homogenesis does not exclude the differences between parent and offspring that continually occur, forming the material for the slow alteration of stocks in the course of evolution (see VARIATION AND SELECTION). Homogenesis means simply that such organism comes into existence directly from a parent organism of the same race, and hence of the same species, sub-species, genus and so forth. From time to time there have been observers who have maintained a belief in the opposite theory, to which the name heterogenesis has been given. According to the latter theory, the offspring of a given organism may be utterly different from itself, so that a known animal may give rise to another known animal of a different race, species, genus, or even family, or to a plant, or vice versa. The most extreme cases of this belief is the wellknown fable of the "barnacle-geese," an illustrated account of which was printed in an early volume of the Royal Society of London. Buds of a particular tree growing near the sea were described as producing barnacles, and these, falling into the water, were supposed to develop into geese. The whole story was an imaginary embroidery of the facts that barnacles attach themselves to submerged timber and that a species of goose is known as the bernicle goose. In modern times the exponents of heterogenesis have limited themselves to cases of microscopic animals and plants, and in most cases, the observations that they have brought forward have been explained by minuter observation as cases of parasitism. No serious observer, acquainted with modern microscopic technical methods, has been able to confirm the explanation of their observations given by the few modern believers in heterogenesis. (P.C.M.) BIOGRAPHY (from the Gr. Bios, life, and yoȧon, writing), that form of history which is applied, not to races or masses of men, but to an individual. The earliest use of the word Bypadia is attributed to Damascius, a Greek writer of the beginning of the 6th century, and in Latin biographia was used, but in English no earlier employment of the word, "biography" has been traced than that of Dryden in 1683, who uses it to describe the literary work of Plutarch," the history of particular men's lives." It is cbvious that this definition is necessary, for biography is not the record of "life" in general, but of the life of a single person. The idea of the distinction between this and history is a modern thing; we speak of "antique biography," but it is doubtful whether any writer of antiquity, even Plutarch, clearly perceived its possible existence as an independent branch of literature. All of them, and Plutarch certainly, considered the writing of a man's life as an opportunity for celebrating, in his person, certain definite moral qualities. It was in these, and not in the individual characteristics of the man, that his interest as a subject of biography resided. The true conception of biography, therefore, as the faithful portrait of a soul in its adventures through life, is very modern. We may question whether it existed, save in rare and acci- | but these, like the Life of Alexander the Great, by Q. Curtius dental instances, until the 17th century. The personage Rufus, were rather historical than biographical. Tacitus described was, in earlier times, treated either from the philo- composed a life of his father-in-law, Agricola; this is a work sophical or from the historical point of view. In the former case, of the most elegant and stately beauty. Suetonius was the rhetoric inevitably clouded the definiteness of the picture; the author of several biographical compilations, of which the Lives object was to produce a grandiose moral effect, to clothe the of the Twelve Caesars is the best-known; this was produced in subject with all the virtues or with all the vices; to make his the year 120. Marius Maximus, in the 4th century, continued career a splendid example or else a solemn warning. The the series of emperors down to Heliogabalus, but his work has consequence is that we have to piece together unconsidered not been preserved. The Augustan History, finished under incidents and the accidental record of features in order to obtain Constantine, takes its place, and was concluded and edited by an approximate estimate. We may believe, for instance, that Flavius Vopiscus. a faithful and unprejudiced study of the emperor Julian, from the life, would be a very different thing from the impression left upon us by the passions of Cyril or of Theodoret. In considering what biography, in its pure sense, ought to be, we must insist on what it is not. It is not a philosophical treatise nor a polemical pamphlet. It is not, even, a portion of the human contemporary chronicle. Broad views are entirely out of place in biography, and there is perhaps no greater literary mistake than to attempt what is called the "Life and Times" of a man. In an adequate record of the "times," the man is bound to sink into significance; even a "Life and Times" of Napoleon I. would be an impossible task. History deals with fragments of the vast roll of events; it must always begin abruptly and close in the middle of affairs; it must always deal, impartially, with a vast number of persons. Biography is a study sharply defined by two definite events, birth and death. It fills its canvas with one figure, and other personages, however great in themselves, must always be subsidiary to the central hero. The only remnant of the old rhetorical purpose of "lives" which clearer modern purpose can afford to retain is the relative light thrown on military or intellectual or social genius by the achievements of the selected subject. Even this must be watched with great care, lest the desire to illuminate that genius, and make it consistent, should lead the biographer to glose over frailties or obscure irregularities. In the old "lives" of great men, this is precisely what was done. If the facts did not lend themselves to the great initial thesis, so much the worse for them. They must be ignored or falsified, since the whole object of the work was to "teach a lesson," to magnify a certain tendency of conduct. It was very difficult to persuade the literary world that, whatever biography is, it is not an opportunity for panegyric or invective, and the lack of this perception destroys our faith in most of the records of personal life in ancient and medieval times. It is impossible to avoid suspecting that Suetonius loaded his canvas with black in order to excite hatred against the Roman emperors; it is still more difficult to accept more than one page in three of the stories of the professional hagiographers. As long as it was a pious merit to deform the truth, biography could not hope to flourish. It appears to have originally asserted itself when the primitive instinct of sympathy began to have free play, that is to say, not much or often before the 17th century. Moreover, the peculiar curiosity which legitimate biography satisfies is essentially a modern thing; and presupposes our observation of life not unduly clouded by moral passion or prejudice. Among the ancients, biography was not specifically cultivated until comparatively later times. The lost "Lives" of Critias were probably political pamphlets. We meet first with deliberate biography in Xenophon's memoirs of Socrates, a work of epochmaking value. Towards the close of the 1st century, Plutarch wrote one of the most fascinating books in the world's literature, his Parallel Lives of 46 Greeks and Romans. In later Greek, the Life of Apollonius of Tyana was written by Philostratus, who also produced a Lives of the Sophists. In the 3rd century, Diogenes Laertius compiled a Lives of the Philosophers, which is of greater interest than a Lives of the Sophists composed a hundred years later by Eunapius. Finally in the 10th century, Suidas added a biographical section to his celebrated Lexicon. In Latin literature, the carliest biography we meet with is the fragment of the Illustrious Men of Cornelius Nepos. Memoirs began to be largely written at the close of the Augustan age, Biography hardly begins to exist in English literature until the close of the reign of Henry VIII. William Roper (1496-1578) wrote a touching life of his father-in-law, Sir Thomas More, and George Cavendish (1500-1561?), a memoir of Cardinal Wolsey which is a masterpiece of liveliness and grace. It is with these two works, both of which remained in manuscript until the 17th century, that biography in England begins. The lives of English writers compiled by John Bale (1495-1563) are much more primitive and slight. John Leland (d. 1552) and John Pits (1560-1616) were antiquaries who affected a species of biography. In the early part of the 17th century, the absence of the habit of memoir writing extremely impoverishes our knowledge of the illustrious authors of the age, of none of whom there are preserved such records as our curiosity would delight in. The absence of any such chronicle was felt, and two writers, Thomas Heywood and Sir Aston Cokayne, proposed to write lives of the poets of their time. Unfortunately they never carried their plans into execution. The pioneer of deliberate English biography was Izaak Walton, who, in 1640, published a Life of Donne, followed in 1651 by that of Sir Henry Wotton, in 1665 by that of Richard Hooker, in 1670 by that of George Herbert, and in 1678 by that of Dr Robert Saunderson. These five reprinted, under the title of Walton's Lives, were not only charming in themselves, but the forerunners of a whole class of English literature. Meanwhile, Fuller was preparing his History of the Worthics of England, which appeared after his death, in 1662, and John Aubrey (1626-1697) was compiling his Minutes of Lives, which show such a perfect comprehension of the personal element that should underlie biography; these have only in our own days been completely given to the public. Edward, Lord Herbert of Cherbury (1583-1648), wrote a brilliant autobiography, first printed in 1764; that of Anne Harrison, Lady Fanshawe (1625-1680), remained unknown until 1829. A very curious essay in biography is the memoir of Colonel John Hutchinson, written by his widow, Lucy, between 1664 and 1671. Margaret Lucas, duchess of Newcastle (1624?-1674), wrote her own life (1656) and that of her duke (1667). The Athenae Oxonienses of Anthony à Wood (1632-1695) was a complicated celebration of the wit, wisdom and learning of Oxford notabilities since the Reformation. In 1668 Thomas Sprat (16351713) wrote a Life of Cowley, which was very much admired and which exercised for many years a baneful influence on British biography. Sprat considered that all familiar anecdote and picturesque detail should be omitted in the composition of a memoir, and that moral effect and a solemn vagueness should be aimed at. The celebrated funeral orations of Jeremy Taylor were of the same order of eloquence, and the wind of those grandiose compositions destroyed the young shoot of genuine and simple biography which had budded in Walton and Aubrey. From this time forth, for more than half a century, English biography became a highly artificial and rhetorical thing, lacking all the salient features of honest portraiture. William Oldys (1696-1761) was the first to speak out boldly; in 1747, in the preface to the Biographia Britannica, he pointed out "the cruelty, we might even say the impiety, of sacrificing the glory of great characters to trivial circumstances and mere conveniency," and attacked the timid and scrupulous superficiality of those who undertook to write lives of eminent men, while omitting everything which gave definition to the portrait. In 1753 the Lives of the Poets, which bore the name of Theophilus Cibber (1703-1758), but was mainly written by Robert Shiels (d. 1753), gave a great deal of valuable information with regard to the personal adventures of our writers. Dr Johnson's Life of Savage (1744), though containing some passages of extreme interest, was a work of imperfect form, but Mason's Life and Lellers of Gray (1774) marks a great advance in the art of biography. This was the earliest memoir in which correspondence of a familiar kind was used to illustrate and to expand the narrative, and Mason's Gray is really the pioneer of almost all modern English biography. For the first time it was now admitted that letters to intimate friends, not written with a view to publication, might be used with advantage to illustrate the real character of the writer. Boswell, it is certain, availed himself of Mason's example, while improving upon it, and in 1791 he published his Life of Dr Samuel Johnson, which is the most interesting example of biography existing in English, or perhaps in any language. As soon as the model of Boswell became familiar to biographers, it could no longer be said that any secret in the art was left unknown to them, and the biographies of the 19th century are all more or less founded upon the magnificent type of the Life of Johnson. But few have even approached it in courage, picturesqueness or mastery of portraiture. In the next generation Southey's lives of Nelson (1813) and John Wesley (1820) at once became classics; but the pre-eminent specimen of early 19-century biography is Lockhart's superb Life of Sir Walter Scott (1837-1838). The biographies of the 19th century are far too numerous to be mentioned here in detail; in the various articles dedicated to particular men and women in this Encyclopaedia, the date and authorship of the authoritative life of each person will in most cases be found appended. Towards the close of the century there was unquestionably an excess, and even an abuse, in the habit of biography. It became the custom a few years or even months after the decease of an individual who had occupied a passing place in the eyes of the public, to issue a "Life" of him; in many cases such biography was a labour of utter supererogation. But the custom has become general, and it is very unlikely, notwithstanding the ephemeral interest of readers in the majority of the subjects, that it will ever go out of fashion, for it directly indulges both vanity and sentiment. What is true of Great Britain is true, though in less measure, of all other modern nations, and it is not necessary here to deal with more than the early manifestations of biography in the principal European literatures. To Switzerland appears due the honour of having given birth to the earliest biographical dictionary ever compiled, the Bibliotheca Universalis of Konrad Gesner (1516-1565), published at Zürich in Latin, Greek and Hebrew, from 1545 to 1549. A very rare work, by a writer of the greatest obscurity, the Prosopographia of Verdier de Vauprivas, published at Lyons in 1573, professed to deal with the lives of all illustrious persons who had flourished since the beginning of the world In medieval and renaissance France there existed numerous memoirs and histories, such as those of Brantôme, into which the lives of great men were inserted, and in which a biographical character was given to studies of virtue and valour, or of the reverse. But the honour of being the earliest deliberate contribution to biography is generally given to the Acta Sanctorum, compiled by the Bollandists, the first volume of which appeared in 1653. This was the first biographical dictionary compiled in Europe, and its publication produced a great sensation. It was confined to the lives of saints and martyrs, but in 1674 Louis Moréri, in his Grand Dictionnaire, included a biographical section of a general character. But the earliest biographical dictionary which had anything of a modern form was the celebrated Dictionnaire historique et critique of Pierre Bayle, in 1696; the lives in this great work, however, are too often used as mere excuses for developing the philosophical and controversial views of the author; they are nevertheless the result of genuine research and have a true biographical view. The Dictionnaire was translated into English in 1734, and had a wide influence in creating a legitimate interest in biography in England. In Italian literature, biography does not take a prominent place until the 15th century. The Lives of Illustrious Florentines, in which a valuable memoir of Dante occurs, was written in Latin by Filippo Villani. Vespasiano da Bistrici (1421-1498) compiled a set of biographies of his contemporaries, which are excellent of their kind. The so-called Life of Castruccio Castracani, by Machiavelli, is hardly a biography, but a brilliant essay on the ideals of statecraft. Paolo Giovio (14831552) wrote the lives of poets and soldiers whom he had known. All these attempts, however, seem insignificant by the side of the autobiography of Benvenuto Cellini (1501-1571), confessedly one of the most entertaining works of the world's literature. A great deal of biography is scattered throughout the historical compilations of the Italian renaissance, and the Lives of the Artists, by Giorgio Vasari (1512-1574), is a storehouse of anecdotes admirably told. We find nothing else that requires special mention till we reach the memoir-writers of the 18th century, with the autobiographies of Count Carlo Gozzi and Alfieri; and on the whole, Italy, although adopting in the 19th century the habit of biography, has rarely excelled in it. In Spanish literature Fernán Pérez de Guzmán (1378–1460), with great originality, enshrined, in his Generations and Likenesses, a series of admirable literary portraits; he has been called the Plutarch of Spain. But, in spite of numerous lives of saints, poets and soldiers, Spanish literature has not excelled in biography, nor has it produced a single work of this class which is universally read. In Germany there is little to record before the close of the 18th century. In the course of the 19th century a new thing in biography was invented, in the shape of dictionaries of national biography. Of these, the first which was carried to a successful conclusion was the Swedish (1835-1857), which occupied 23 volumes. This dictionary was followed by the Dutch (1852-1878), in 24 volumes; the Austrian (1856-1891), in 35 volumes; the Belgian (which was begun in 1866); the German (1875-1900), in 45 volumes; and others, representing nearly all the countries of Europe. England was behind the competitors named above, but when she joined the ranks a work was produced the value of which can hardly be exaggerated. The project was started in 1882 by the publisher George Smith (1824-1901), who consulted Mr (afterwards Sir) Leslie Stephen. The first volume of the English Dictionary of National Biography was published on the 1st of January 1885, under Stephen's editorship. A volume was published quarterly, with complete punctuality until Midsummer 1900, when volume 63 closed the work, which was presently extended by the issue of three supplementary volumes. In May 1891 Leslie Stephen resigned the editorship and was succeeded by Mr Sidney Lee, who conducted the work to its prosperous close, bringing it up to the death of Queen Victoria. The Dictionary of National Biography contains the lives of more than 30,000 persons, and has proved of inestinable service in elucidating the private annals of the British people. (E. G.) BIOLOGY (Gr. Bios, life). The biological sciences are those which deal with the phenomena manifested by living matter; and though it is customary and convenient to group apart such of these phenomena as are termed mental, and such of them as are exhibited by men in society, under the heads of psychology and sociology, yet it must be allowed that no natural boundary separates the subject matter of the latter sciences from that of biology. Psychology is inseparably linked with physiology; and the phases of social life exhibited by animals other than man, which sometimes curiously fcre shadow human policy, fall strictly within the province of the biologist. On the other hand, the biological sciences are sharply marked off from the abiological, or those which treat of the phenomena manifested by not-living matter, in so far as the properties of living matter distinguish it absolutely from all other kinds of things, and as the present state of knowledge furnishes us with no link between the living and the not-living. These distinctive properties of living matter are The pro BIOLOGY 1. Its chemical composition-containing, as it invariably does, one or more forms of a complex compound of carbon, hydrogen, oxygen and nitrogen, the so-called protein or albumin perties of (which has never yet been obtained except as a product of living bodies), united with a large proportion of water, and forming the chief constituent of a substance which, in its primary unmodified state, is known as protoplasm. living matter. 2. Its universal disintegration and waste by oxidation; and ils concomitant reintegration by the intussusception of new matter. A process of waste resulting from the decomposition of the molecules of the protoplasm, in virtue of which they break up into more highly oxidated products, which cease to form any part of the living body, is a constant concomitant of life. There is reason to believe that carbonic acid is always one of these waste products, while the others contain the remainder of the carbon, the nitrogen, the hydrogen and the other elements which may enter into the composition of the protoplasm. The new matter taken in to make good this constant loss is either a ready-formed protoplasmic material, supplied by some other living being, or it consists of the elements of protoplasm, united together in simpler combinations, which consequently have to be built up into protoplasm by the agency of the living matter itself. In either case, the addition of molecules to those which already existed takes place, not at the surface of the living mass, but by interposition between the existing molecules of the latter. If the processes of disintegration and of reconstruction which characterize life balance one another, the size of the mass of living matter remains stationary, while, if the reconstructive process is the more rapid, the living body grows. But the increase of size which constitutes growth is the result of a process of molecular intussusception, and therefore differs altogether from the process of growth by accretion, which may be observed in crystals and is effected purely by the external addition of new matter-so that, in the well-known aphorism "" grow as applied to stones signifies a of Linnacus, the word " totally different process from what is called "growth" in plants and animals. 3. Its tendency to undergo cyclical changes. In the ordinary course of nature, all living matter proceeds from pre-existing living matter, a portion of the latter being detached and acquiring an independent existence. The new form takes on the characters of that from which it arose; exhibits the same power of propagating itself by means of an offshoot; and, sooner or later, like its predecessor, ceases to live, and is resolved into more highly oxidated compounds of its elements. Thus an individual living body is not only constantly changing its substance, but its size and form are undergoing continual modifications, the end of which is the death and decay of that individual; the continuation of the kind being secured by the detachment of portions which tend to run through the same cycle of forms as the parent. No forms of matter which are either not living, or have not been derived from living matter, exhibit these three propertics, nor any approach to the remarkable phenomena defined under the second and third heads. But in addition to these distinctive characters, living matter has some other peculiarities, the chief of which are the dependence of all its activities upon moisture and upon heat, within a limited range of temperature, and the fact that it usually possesses a certain structure or organization. Life con perature. The properties of living matter are intimately related to temperature. Not only does exposure to heat sufficient to coagulate protein matter destroy life, by demolishing the molecular structure upon which life depends; but all vital activity, all phenomena of nutritive growth, by tem movement and reproduction are possible only between certain limits of temperature. These limits may be set down as from a little above the freezing point of water to a little below the boiling point It is to be noted, however, that these limits apply to the living matter itself, and many of the apparent exceptions are due to cases in which the living matter is enclosed in protective wrappings capable of resisting heat and cold. In many low organisms, such as the spores of bacteria, the thick, non-conducting wall may preserve the living protoplasm from subjection to external temperatures below freezing point, or above boiling point, but all the evidence goes to show that applications of such cold or heat, if prolonged In warm-blooded animals, such as birds and mammals, protective or arranged so as to penetrate to the living matter, destroy life. mechanisms for the regulation of temperature enable them to endure exposure to extreme heat or cold, but in such cases the actually living cells do not appreciably rise or fall in temperature. A variation of a very few degrees in the blood itself produces death. Life and organiza tion. Recent investigations point to the conclusion that the immediate cause of the arrest of vitality, in the first place, and of its destruction, in the second, is the coagulation of certain substances in the protoplasm, and that the latter contains various coagulable matters, which solidify at different temperatures. And it remains to be seen, how far the death of any form of living matter, at a given temperature, depends on the destruction of its fundamental substance at that heat, and how far death is brought It may be safely said of all those living things which are large about by the coagulation of merely accessory compounds. enough to enable us to trust the evidence of microscopes, that they are heterogeneous optically, and that their different parts, and especially the surface layer, as chemically; while, in most living things, mere heterocontrasted with the interior, differ physically and geneity is exchanged for a definite structure, whereby the body is distinguished into visibly different parts, which possess different structure are said to be organized; and so widely docs organizapowers or functions. Living things which present this visible tion obtain among living beings, that organized and living are not unfrequently used as if they were terms of co-extensive applicability. This, however, is not exactly accurate, if it be thereby implied that all living things have a visible organization, as there are numerous forms of living matter of which it cannot properly be said that they possess either a definite structure or permanently specialized organs: though, doubtless, the simplest particle of living matter must possess a highly complex molecular structure, which is far beyond the reach of vision. The broad distinctions which, as a matter of fact, exist between every known form of living substance and every other component of the material world, justify the separation of the biological sciences from all others. But it must not be supposed that the differences between living and not-living matter are such as to justify the assumption that the forces at work in the one are different from those which are to be met with in the other. Considered apart from the phenomena of consciousness, the phenomena of life are all dependent upon the working of the As has been said, a large proportion of water enters into the same physical and chemical forces as those which are active in vitality " and "vital force" to denote the causes of certain composition of all living matter; a certain amount of drying the rest of the world. It may be convenient to use the terms arrests vital activity, and the complete abstraction " and "electrical force" to denote others; but it of this water is absolutely incompatible with either great groups of natural operations, as we employ the names of electricity' actual or potential life. But many of the simpler ceases to be proper to do so, if such a name implies the absurd electricity" and "vitality" are entities forms of life may undergo desiccation to such an extent as to arrest their vital manifestations and convert them assumption that " into the semblance of not-living matter, and yet remain poten-playing the part of efficient causes of electrical or vital phenotially alive. That is to say, on being duly moistened they return to life again. And this revivification may take place after months, or even years, of arrested life. Life conditioned by moisture. 64 66 mena. A mass of living protoplasm is simply a molecular machine of great complexity, the total results of the working of which, or its vital phenomena, depend-on the one hand, |