Respiration is at heart a chemical process, a fact which some students are slow to learn, but which is fundamental.

There is no reason known to the writer why Reproduction should always be found at the latter end of a general treatise on physiology, since no apology need be offered for discussion of this base-function. It "goes" at the end, however, as well as anywhere else. In the majority of textbooks, even to-day, it certainly is discussed inadequately, a bare outline being given, and the entire hygienic aspect - the only aspect in which the majority of young men and women really need information-is wholly ignored. In many schools it is not customary to systematically teach this subject at all, apparently not altogether out of "modesty," but because every medical faculty realizes that this ordinarily is the first chapter of the textbook to become really familiar to the student: it has native and dynamic interest for every normal adolescent.

Laboratory Physiology, as already has been suggested, is an art in itself, a highly technical art, moreover, based on science. Every year it is more practical, applying itself more widely and also in more detail to the needs of practical medicine, and of hygiene, making itself in short more and more useful (never was it by any possibility ornamental).

Looking

Recent Advance in Physiology. back a generation, comparing Dalton's textbook with the latest edition of Howell or of Bainbridge and Menzies, it is clear that the advance in the science as a whole is dominatingly metabolic. This indeed was what was lacking 20 years ago to round out the science beyond the organic mechanics which then largely it was. Still considerable progress has been made in neurology, in nutrition, and in the physiology of the skin.

In choosing a dozen or more augmenting topics for mention as of especial import in the advance of physiology, it is almost impossible to suit the tastes of any observer besides the writer! Still, perhaps these subjects are really those that have developed most importantly for science in general:

The more recondite composition of the blood has been very successfully studied by many. Immunity, sera, anaphylaxis, acidosis, etc., are physiologic topics studied mostly by other branches of medicine, but each chemical and not part of the ingenious fairy-story of "ceptors" and so on which originated in Germany. The dynamic factors of the blood have been much developed, especially as the new backbone, so to say, of the newest branch of physiology called by some endocrinology, the science and art of the ductless glands. Much has been learned at Harvard about adrenin and pituitrin and their relations to the dynamic "drives" of the organism during anger for example. Vasoconstriction, quicker coagulation, antifatigue effect, and an increase of blood-sugar are somehow topics conspicuous in this new work.

Many plant-pollens give special cases of hayfever because their protein is reacted too violently by the blood-proteins: this is a type of a new group of blood-reactions whose study properly is on a physiologic base.

Fatigue in its more rational aspects (involving the actual living of the actual animal and

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not the actual dying of some abstracted portion of an animal) has been studied extensively in part as "war-work" toward the maximal production of munitions, etc. Columbia has led in this work here in America.

Integration has been appreciated as never before under the influence of psychology. Less and less attention is paid to the phenomena exhibited by protoplasm in its dying stages — as dying every isolated organ must be. The principle is capable of very much further application still in both theoretic and practical physiology. A materialist, for example cannot be possibly really wise as a physiologist, however good an anatomist he may develop into.

The movements of the alimentary canal, both gross and minute, have been studied with much success. It is beginning to be recognized at last that where contractile tissue is there is movement! The Roentgen rays have revealed some of the complex movements of the gut, 18 years ago, and now the finer movements, e.g., of the villi, remain to be described. Nearly five years ago I called attention to their movement and to one of their possible ulterior absorptive functions: "The 4,000,000 villi of the intestine, rich in smooth muscle and sympathetic nerves as well as in epithelium, probably adapt the blood's content of the nutritive lipoids and proteins to the varying immediate needs of the nerve-cells, and may besides send inward sympathetic influences which, fusing, possibly in the brain, become euphoric."

Dietetics has made strides, especially in the direction of applied economic physiology. The old matter of doubt as to the safe-minimum of protein has not been clarified to everyone's satisfaction.

The integrating nervous system has become better known in certain of its functions. The sensory side of the autonomic (itself relatively a recent "discovery") has been developed as Remak's fibres, thus laying more of the physical basis of the subconscious aspects of mind. The cerebral cortex has revealed some of its functions on a basis of psychomotion, especially in the way of restraint. Work has been done on the physiology (vasomotion and keinesthesiology mostly) of sleep. The reflexes have been studied in many directions, practical and theoretic. The senses have been investigated in new ways, on one hand highly technical and on the other practical and popular, a new series of books on the senses helping the latter purpose. Vasomotion has been getting on to a gratifying

extent.

The neuro-musculo glandular system, mechanism of efficiency, has received much attention, especially in England and in some of the physical-education schools of America. The all-or-none principle has been of use in understanding many things in regard to skill. The relations of physiology to exercise has been developed in many directions; and those of satisfaction to the dynamic aspects of work - the so-called "stheneuphoric index" or energy-joy ratio. The rehabilitation of one hellwar crippled and shocked is sure to give the psychological physiology of skill a chance to develop far in theory as well as in practice.

Dental physiology has gone on, largely in the directions of electrical and pathological and prosthetic physiology.

The skin has been revealing some of its hidden mysteries, and proves to be an organ of pre-eminent general importance to the individual. If I may again repeat part of an article summary of nearly five years ago:

The integrated epicritic impulses (from the skin and mucosa) appear to have predominance in human physiologic euphoria, two possible means of stimulation being evaporation and oxidation.

A list of the more or less influential elements of the skin would include the complex vasomotor mechanism; the arrectores pilorum muscles; afferent sympathetic dendrites, the peculiarly efficient epidermis, sweat glands, sebaceous glands; Meissner's corpuscles, the terminal cylinders of Ruffini, tactile menisci, the nerve-rings of Bonnet (?), Vater-Pacinian corpuscles, free nerve-endings, heat-receptors, coldreceptors, pain-receptors, pleasure-receptors, and possibly tickle-receptors.

Air that is dead (i.e., not moving); humid and too warm; humid and too cold; or lacking in oxygen, is a chief occasion of organic dysphoria. Physiologically these conditions are lacks, lack of movement over the skin, lack of the optimum temperature, lack of dryness (evaporation so being lessened), and lack of dermal oxygen, possible reflex determinant in part of pulmonary respiration.

Arterial tension has been actively studied in many places and is about to reach important practical conclusions as we learn more and more of the intricate controls of vasomotion. A new "continuous," method has been devised for the study and record (hemobarogram) of the ever-varying blood-pressures termed systolic and diastolic, respectively. From the Proceedings of the American Psychological Association (December 1916) the following slightly modified excerpts may be added to indicate the status of one phase of the physiology of bloodpressure at that time. Nine or ten thousand measurements sanction these tentative propositions, as the hemobarograms show:

Arterial stuffing and constriction_are very active and variable in all persons. Peripheral arterial tension is by far the most sensitive and easiest index of vasomotor rearrangement correlate to activity mental or bodily. The doubleness of blood-pressure measurement ("systolic" and "diastolic") makes possible a partially differential index of activities:

The "systolic" tension represents especially the ever-changing output of the left heart, which latter is quickly variable in size (Gesell) as well as in the frequency of its contraction. The diastolic tension is more dependent on the autonomic vasomotion, direct and reciprocal. Thus the systolic variations are more directly mental, and the diastolic more somatic and vegetative.

The ordinary systolic pressure-range is about 10 millimeters Hg, increasing to 40 or 50 or more in "mental" activity of a somewhat greater intensity. The usual diastolic range is about 8 millimeters Hg, save in old persons, and it has a lower maximum. Vasotension is a ready index of the intellectual and affective psychophysical dynamism ("power of concentration") of an individual, and as such has value as a mental test; it is also a useful index of "nervousness" and of mental derangement perhaps.

Aments (except microcephs?) sometimes have a spontaneous systolic range of no more than 2 or 3 millimeters Hg for many minutes at a time, and a mental activity-range of 5 or 10 millimeters. Complete dements exhibit something of the same arterio-stasis but with a tendency to large progressive excitement-rises not observed in aments. One microceph had a large and quick diastolic range and a normal systolic curve. Imbeciles and morons show varying degrees of the systolic plateau more or less according to mental status and dynamism; but there are many exceptions.

No personal, racial, sexual or age-differences in the variability have appeared; each hemobarogram is unique and always an interesting and accurate "human document."

Sudden mental activity, apparently of any sort (e.g., multiplication, imagination of any kind of personal activity, transfers of the attention-line, attention to the arm-sensations, dynamic associations, unpleasant or pleasant effects); active inhibition; breath-holding, and gradual subconscious increase of psychophysical tonus, increase both the systolic and the diastolic tensions, especially the former; so does physical exertion proper.

Really passive relaxation of the muscles and of the mind; quiet, prolonged recall of happiness; sleep-suggestion; humor; deep breathing, and usually sensations of pleasure not allowed to excite, cause a lowering of both pressures. Marked rises in both tensional phases occur without conscious accompaniment, suggestive if not demonstrative of the subconscious actions of mind. Reciprocal variation of the systolic and the diastolic is very frequent, yet in some cases the two parallel each other for many minutes at a time. True emotion (adrenin and blood-sugar are suggested) lasts much longer than pretended emotion and "causes" (?) more variation.

Imaginary neuromuscular fatigue exerts a strong vasomotor influence. Lapsus attentionis lowers both tensions suddenly and far.

These are some of the chief personal considerations. The medical relations are too complex to be reported; less has been accomplished in this field of application.

Very numerous topics have been developed by physiologists since the preceding revision of this Encyclopedia was made, but these seem to the present writer to be fair examples of the most important directions. The World War will deflect the research-activities of the science into more practical (if not more useful) lines, at least for a time. The average physiologist will then have a broader mind and will realize, often for the first time, that his great and fundamental science; as the dealing with organic functions, is more than a study of "nerve-muscle-preparations," that it may be made one of the two foundation sciences of personal human life.

one

GEORGE VAN NESS DEARBORN, Medical Corps, United States Army. PHYSIOLOGY OF PLANTS. See PLANTS, PHYSIOLOGY OF.

PHYSIOLOGY OF TASTE, or PHYSIOLOGIE DU GOÛT. This work may be compared in a distant way to the 'Compleat Angler of Isaak Walton. It is a similar repertory of information, precept, anecdote and

personal reflection, a similar stream of pleasant talk by a charming companion who discourses most entertainingly of what has been, after his business, the most unfailing interest of his life. Its author, Brillat-Savarin (q.v.) (1755–1826), was an honored magistrate and jurist, but his fame rests wholly on this volume of "meditations of transcendent gastronomy," as he calls it with mock grandiloquence and with a humorous reference, perhaps, to Lamartine's 'Poetical Meditations, which had been the great literary success a few years before. He worked at it affectionately for many years, and only gave it to print, and then anonymously, a year before his death. Its contents are most various. First come 30 "meditations" on such matters as the senses, taste, smell, appetite, thirst, the pleasures of the table, digestion, rest, sleep, dreams, diet, corpulence, fasting, the history of cooking, in which physiological fact and theory alternate with stories of remembered feasts, bits of strange lore from far afield with descriptions of culinary chefsd'œuvre that makes your mouth water, racy anecdotes with practical recipes. Then, as if the meditations had not afforded him latitude enough, he adds 27 variétés, "miscellanies." But various as are the contents, they all turn about the business or pleasure of eating. Gastronomy is declared to be the chief of all sciences. "The destiny of nations depends on how they are fed," and "Tell me what you eat and I will tell you who you are," are among the aphorisms which serve as its basis. And the intentional mock grandiloquence of the style and the apparent levity of the author should not deceive us as to the seriousness of the work. There is much in the book, in its intention, at least, to justify the title, "physiology of taste." It was one of the first attempts to approach the spectacle of human conduct from the physiological side. It is perhaps not without significance that Balzac admired it much and afterward wrote a 'Physiology of Marriage' and a Physiology of Dress.' However, Balzac recognized that the charm of the book lies, not in the matter, but in the style and in the genial, lively and humorous personality that shines through it. Consult the English translation by Anderson, R. E., Gastronomy as a Fine Art' (London and New York 1877).

ARTHUR G. CANFIELD. PHYSOSTIGMA. See CALABAR BEAN. PHYTOGEOGRAPHY. See PLANT GEOG

RAPHY.

PHYTOLACCASEÆ. See POKEWEED. PI-BESETH, pē-bā'sěth. See BUBASTIS. PIA MATER, pi'a ma'ter the innermost of the three membranes investing the brain and spinal cord. See BRAIN; ARACHNOID Mem

BRANE.

PIACENZA, Pietro, Italian clergyman: b. Piacenza, Italy, 21 Jan. 1847. He was educated at Alberoni's College, Piacenza, and ordained to the priesthood in 1869. From 1870 to 1878 he was professor of history and liturgy, at Piacenza Seminary; from 1878 to 1897 he was archpriest and pastor of Fiorenzuola, and after 1897 archpriest of the cathedral of Piacenza. Since 1904 he has been visitor apostolic of Rome and its district, and after 1907 professor of liturgy in the Roman Seminary. Dr. Piacenza has

51

published Storia del B. Gregorio X (1876); "Quæstiones Liturgica (1887); Il Rito della consacrazione di un vescovo (1899); (Un curioso documento della giovinezza di Pietro Giordani (1901), etc., and contributions to Ephemerides Liturgica, Archivo storico, etc.

PIACENZA, pē-ä-chĕn'zä (ancient PLACENTIA), Italy, city, capital of the province of Piacenza; one-third mile south of the Po River; 43 miles southeast of Milan and 35 miles northwest of Parma. It is a fortified city and has always been considered of great strategic and commercial importance. The fortifications are kept in repair and improved from time to time as new defense methods are introduced. The city was founded 219 B.C. by the Romans. About 20 years later it was destroyed by the Gauls. When the Via Emilia, a Roman military road, was constructed, the western terminus was at Piacenza. The city entered the Lombard League in the 12th century, later fell under the domination of the Visconti, the Sforza, and the popes. In 1545 Pope Paul III presented it together with Parma (q.v.) to his son Pier Luigi Farnese. From then on its political fortunes followed those of Parma.

Among the historic buildings of Piacenza is the ancient church, San Sisto, rebuilt in 14991511, for which Raphael, about 1515, painted. the Sistine Madonna. This picture was sold, in 1753, to Frederick Augustus of Saxony and is now in the Dresden Gallery. Other noted buildings are the cathedral (1122), in which there are paintings by Guercino, Carracci and others. The church of Santa Maria di Campagna has fine frescoes by Pordenone; the square has some fine equestrian statues. The public library has about 120,000 volumes. The Palazzo Municipale is an impressive building dating back to 1281. The huge, uncompleted Palazzo Farnese, begun in 1558, now serves as a military barrack. It has modern theatres, hospitals and educational institutions. It has considerable manufacturing interests, especially in silk, cotton and woolen goods, pottery, wine, cheese and machinery. In the vicinity are valuable marble quarries. Pop. commune about 40,000. Consult 'Monumenta Historica ad Provincias Parmensem et Placentinam Pertinentia' (8 vols., Parma 1855-60); Giarelli, (Storia di Piacenza' (2 vols., Piacenza 1889); Jordan, L., 'Die Renaissance in Piacenza) (in Archiv für Kultur-Geschichte,' Vol. V, Berlin 1907); Siro Corti, 'Provincia di Piacenza' (Turin 1893).

PIACERE is D'Annunzio's first novel, and was first published in 1889, when he was 26 years old. A more fitting title than the one which the author gave it is that of the English translation by Georgina Harding, The Child of Pleasure' (Boston 1910), which in turn was suggested by the still more illuminating and apt title of the French translation, 'L'Enfant de la Volupté.' The story is that of a workless yet wealthy young man of the Italian nobility who has a love for, and succeeds in winning, several women, and who has more momentary affairs with a great many others, all of them, however, of his own class. The two most interesting parts of it are the description of a horse race for "gentlemen" riders, in which the hero races against a friend the love of whose mistress, the wife of a mutual

friend, he has appropriated, and the description of the duel on the following day between the winner (of the race as well as of the lady) and the loser, which event interrupts the lovemaking of the former because of a serious wound received. Both incidents are familiar to novel readers. There is no plot. The book is a painstaking exposition of an artificial state of mind and of sensual emotions which it engenders. The attitude toward women therein displayed is not wholesome: they merely present possibilities for material pleasure. The very completeness of its psychological detail renders it at least monotonous, and the normal, healthly mind conceives no sympathy, to put it mildly, with D'Annunzio's hypocritical and obnoxiously aristocratic hero. In workmanship the story does not present a high degree of skill and a number of the links are plainly conventional. However, it must be remembered that it is a work of youth. Consult Sedgwick, H. D., 'Essays on Great Writers' (Boston 1903).

AMERICO U. N. CAMERA.

PIAGGIA, Carlo, Italian explorer: b. Lucca, Italy, about 1822; d. Sennaar, Sudan, 17 Jan. 1882. He went to Egypt when young, was with Antinori in Bahr-el-Ghazal 1860; went with Gessi to the lakes of the Nile in 1876 and was the first European among the Nyam-Nyam. His ethnographic collection was acquired by the Berlin Museum. He published 'Dell' arrivo fra i Niam-Niam' (Lucca 1877).

PIANISSIMO, the superlative of piano (Italian for soft and low); piano is used in music in contradistinction to forte. The symbols for these terms are pp. and p. Some composers, especially Verdi, Berlioz and Tschaikovsky use the symbol pppp. and even ppppp. to express that they desire the softest pianissimo possible, while many others frequently indicate this by ppp. See MUSIC.

PIANKISHAW (pi-ǎn'kē-shâ) INDIANS, a small American tribe of the Algonquian family, originally a part of the Miamis (q.v.). The tribe never numbered over 1,000. They removed to the Indian Territory, now Oklahoma, from Kansas in 1867, after selling all their lands in the latter State. They are now known under the name of Peoria, of which in 1906 there were only 192 left, none of whom was of pure blood. Consult Hodge, F. W., ed., 'Handbook of American Indians North of Mexico (Part II, Washington 1910).

PIANOFORTE, a stringed musical instrument commonly known as a “piano,” and essentially consists of a series of stretched, graded and tuned wires which are struck by felt-covered hammers by the operation of keys conveniently arranged in a keyboard. The term, "pianoforte," which is the original term designating the instrument, is derived from the Italian "piano," soft + "forte," loud; while the term "piano," usually designated by p., is a sign used in music to denote softness, that is, the strain where the indication occurs is to be played with less than the average intensity. Similarly, pp., or ppp., abbreviations for "pianissimo," signify very soft.

The pianoforte is probably the most extensively used of all musical instruments. It was evolved directly from the clavichord and harpsichord, which were undoubtedly elaborations of

the monochord or pitch-carrier with one string, although even the approximate date or the name of the inventor who first put keys to a monochord and called it a clavicordium is quite unknown. Virdung, in his 'Musica Getutscht,' published in 1511, states his inability to ascertain those facts, although it is well known that Pythagoras, in the 6th century B.C., measured a vibrating string stretched between raised bridges on a resonance box, and by shifting those bridges he accurately determined the intervals of the Greek diatonic scale. It is supposed that Pythagoras obtained the monochord embodying the principle of the stopped string upon a finger-board from Egypt, where it had been known for ages before his time. After Pythagoras, the monochord became, in Greece and Europe, the canon or rule for the measurement of musical sound intervals, and continued to be so employed up to the 11th century, A.D., when it was transformed into a polychord of four strings, to facilitate the melodic division of the Gregorian tones - the PlainSong of the Church as used in the Ritual, and were known under a great variety of names such as clavichord, clavicordium, spinet, virginal and regal.

The early clavichords had a compass of four octaves. The natural keys were made of citron wood and the sharps of ebony. The damper was a narrow band of felt attached with glue to the hitch-pin block, opposite to the wrest-pin block, and the bridge was curved. As they were strung with wires in equal lengths, they were for a long time regarded as sets of monochords, the scaling being effected by the line of the tangents attached to the keys on the lefthand side of the player, while the three or more sounding-board bridges rested upon the narrow belly on the right. Owing to the length of the scale the longer instruments were not capable of being tuned higher, giving them a weak but delicate tone which responded to the gradations of the player's touch. The tangents were upright blades of brass fastened into the keys and beaten out at the top so as to touch equally the one string or the two or three unison strings forming a note. The tangents thus constituted a series of bridges or sound exciters, and each of the little groups of strings thus formed was acted upon by two or sometimes three or four tangents to obtain as many notes. The damping was contrived with a cloth interwoven among the strings behind the line of tangents. This cloth instantly dampened the vibration of the strings when the finger released the key and the tangent quit the string.

FIG. 1.-Queen Elizabeth's Virginal, South Kensington Museum, London.

Clavichords with pedals are mentioned by Virdung and Reynvaan, and are also particularly described by Adlung, indicating that some of the instruments had two octaves and a note of pedals attached to a separate clavichord pedalier and "fretted," there being three strings in the lower and four in the upper range for each pedal note. The terms virginal or spinet

generally indicate one and the same instrument without regard to form of construction, but practically limited to a plectrum (jack) clavier with one string only to each note (see Fig. 1). Its earliest recorded name is the clavicymbolum, occurring in the rules of the Minnesingers under the date of 1404. It is the Latin for psaltery, an instrument of the dulcimer kind, to which a keyboard was added and suggests an ecclesiastical or monastic origin. Virginal was the English name of the spinet, and was so called probably on account of its appropriateness for girls as compared with the contemporary lute which was a more difficult and manly instrument, rather than the assumption that Queen Elizabeth was a skilful performer on it, especially as the name was current in the reign of her grandfather, Henry VII. According to Scaliger, who wrote in the latter part of the 15th century, the name spinet is derived from the little quill point or plectrum, as an improvement upon the instruments previously known as monochordum and harpsichordium, a keyboard psaltery of harp shape. On the other hand, the Italian expert, Signor Ponsicchi, attributes it to a Venetian maker, who signed and dated an instrument of this kind "Ioannes Spinetus, Venetus Fecit; A.D. 1503." The virginal that is assosociated with Queen Elizabeth is now in the South Kensington Museum, London, and may be described as an Italian pentagonal spinet aled dow

(see Fig. 2). Italian spinets were made of cypress wood, and as the utmost vibration was sought for by the makers, both case and belly were constructed of that material. They consisted of two cases the inner rough, but possessing a free and satisfying quality of tone, while the outer received great care in workmanship and was often beautifully decorated. The pentagonal or heptagonal spinets had false cases like the clavicumboli or harpsichords, from which they could be removed when required for performance, while the oblong Italian makes were inseparable from the outer case like the modern pianos. Until the 17th century, the keyboard was usually an external addition to the case, when Rosso, a Milanese maker, set it back into the body of the instrument, a recessing which was generally copied afterward (see Fig. 3).

The harpsichord is a double, treble or quadruple spinet, the sounds being excited by a jack and quill plectrum, as in the case of the virginal or spinet. More exactly stated, instead of having one string to a note, as in the virginal or spinet, it has two, three and sometimes four strings to a note, which, with the exception of the common features of the case, sound-board,

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FIG. 3.-Clavichord, Taphouse Collection, Oxford. yond the capacity of the clavichord, but in expressiveness depending upon touch its power is much less than either.

The harpsichord was a much favored musical instrument during the 17th century, occupying the place now filled by the grand piano, and while not so much a solo instrument, it was of considerable importance in the orchestra, its player generally assuming the responsibility of conductor. The complex character of its mechanism required a larger and differently shaped case to that of the spinet and prefigured that of the grand piano, the wing-shape giving rise to the German name fluegel, also kielfluegel, from the plectrum (kiel, quill) producing the sound. With the Italians-it was known as the clavicembolo, while the French called it clavecin. In the English term harpsichord, the harp disposition is recognized in contrast to the trapeze shape of the spinet, which appeared about the same time the earlier part of the 15th century.

The description of a very fine example of a Roman harpsichord in the South Kensington Museum, London, inscribed and dated "Heironymus Bononiensis Facietat Romae, MDXXIX,» will serve to illustrate the general character of the instruments of that time. It has one keyboard and two unison strings to each note; boxwood natural keys, with an apparent compass of nearly four octaves, E to d3, which by a short octave in the bass becomes C to d3. In the Italian instruments no change of power was attainable by stops, while the pedals, as in the