PHYSIOLOGY 



PIANOFORTE 



163 



acceptable by Darwin's work, is the great harmon- 

 iser of all science. 



This history of physiology may be shortly sum- 

 marised ax follows. Even to early inquirers it was 

 obvious that many of the life-pnx-esses of animals 

 are the result of the action of a set of machines, 

 which, as we know, were supposed to lie kept in 

 action by the 'vital spirits.' These machines were 

 culled organs, ami the work performed was spoken 

 of as their functions. The whole body was con- 

 ceived of a* made np of various organs, and the 

 labours of physiologists were directed towards dis- 

 covering their functions, a work which to this day 

 is incomplete. This may lie calleil the first phase 

 of physiological philosophy ; it lasted until the 



prmmugatimi of the cell-theory and the rapidly fol- 

 lowing discovery of protoplasm. The idea of pro- 

 toplasm is to natural science of nearly as much 

 importance as the doctrines of the conservation of 

 matter and energy are in chemistry and phy-ir-. 

 The chief lalxmrs of physiologists for a very long 

 time will lie directed towards attaining exact concep- 

 tions of the nature of this protoplasm in terms of 

 chemistry and physics. The old question of animal 

 and vital spirits is still unsolved ; we are not able 

 to say whether there is any abrupt distinction 

 between ordinary matter and that which is railed 

 living matter, nnd which forms ' the physical basis 

 of life.' Is it merely that living matter is more 

 complex and unstable than ordinary matter, and 

 therefore far more sensitive to external impulses 

 in the form of ethereal and molecular vibrations ; 

 or is there some special vital force at work? If we 

 fully understand the first theory we shall probably 

 lielieve that there is no such vital force. At any 

 iiit.- the surest path to its discovery lies in deter- 

 mining how far the olyectiee phenomena of life are 

 explicable in terms of ordinary chemical and phy- 

 -ical laws. When we find any activity of living 

 matter which we can be certain cannot I* so 

 explained, then, and not till then, may we postu- 

 late a vital force. Supposing such a discovery ever 

 to lie made, it is necessary to observe that it will 

 merely widen our chenii.-try and physics. The dis- 

 cussion of the subjective consciousness of life is an 

 entirely separate one. Ordinary philosophy postu- 

 lates two entities, matter and spirit ; Materialism 

 holds that matter when it reaches a certain *ta0 

 of complexity l>ecomes conscious; Monism, which 

 is becoming the fashionable scientific creed, teaches 

 that matter in motion and consciousness are the 

 two sides one seen from without, the other felt 

 from within of a single entity. 



We may fitly close by quoting Foster's statement 

 of the present problems of physiology. He speaks 

 of them as threefold. ' ( 1 ) On the one hand, we 

 have to search the laws according to which the 

 complex unstable food is transmuted into the still 

 more complex and still more unstable living flesh, 

 and the laws according to which the living sub- 

 stance breaks down into the simple, stable, waste 

 products, void, or nearly void, of energy. (2) On 

 T he other hand, we have to determine the laws ac- 

 cording to which the vibrations of the nervous sub 

 M originate from extrinsic and intrinsic causes. 

 the laws according to which these vibrations pa-- 

 to and fro in the body, acting and reacting upon 

 each other, and the laws according to which they 

 finally break up and are lost, either in those larger 

 swings of muscular contraction or in some other 

 way. (3) And lastly, we have to attack the 

 abstruser pioblems of how these neural vibrations, 

 often mysteriously attended with changes of con- 

 IMICSS, as well as the less subtle vibrations of 

 the contracting muscles, are wrought out of the 

 explosive chemical decompositions of the nervous 

 and muscular substances i.e. how the energy 

 of chemical action is transmuted into, and serves 



as the supply of that vital energy which appears as 

 movement, feeling, thought.' 



See, besides the articles named above and at ANATOMY, 

 tli.i- on ANIMAL, ANIMAL CHEMISTRY, ANIMAL HEAT, 

 DIET, FOOD, DEATH, LIFE, Ac. ; the elementary primer 

 of physiology by Michael Foster; the elementary text- 

 book by Huxley; text-books by Foster (5th ed. ), 

 Landois and Stirling, M'Kendrick ; Physiolo<iical and 

 Patltnloyiral Chemistry, by Bnnge, trans, by Wooldridge 

 (1890); Chfmirat Pltysioloyy and Pathotmjy, by Halli- 

 burton (18911; Comfmratire Physio/oiii/ and Anatomy, 

 by Jeffrey Bell ( 1887 ) ; Ency. Brit, article ' Physiology,' 

 by Kuster. 



Physostigma. See CALABAR BEAN, the 

 alkaloid of which, a valuable drug, is called Eserin 

 or Physostigmin. 



Physostoini. See BONY FISHES. 



Phytelruhas. See IVORY (VEGETABLE). 



Piarenza. a city of Northern Italy, on the 

 right bank of the I'o, a little below its confluence 

 with the Trebbia, by rail 43 miles SE. of Milan 

 and :{."> N\V. of Parma. Situated at the end of the 

 Via .Kmilia and at the last convenient crossing- 

 place eastwards on the Po, it has always lieen an 

 imi>ortantcity, Ixith strategically ami commercially, 

 since its foundation (as Plaren'tia) by the Romans 

 in 219 B.C. It is defended with bastioned walls and 

 an outer ring of forts. Its streets are broad and 

 regular, but many of them unfrequented and grass- 

 grown. The cathedral, in the Lombard-Romanesque 

 style ( 1122- 1233), has an immense crypt, a campanile 

 223 feet high, and paintings by L. Carracci, Guer- 

 cino, and others. The church of Sant' Antonino, 

 the original cathedral, was founded in 324, but has 

 IM-CII several times rebuilt. The church of Santa 

 Maria delta Campagna is adorned with line frescoes 

 by I'ordenone; and it was for San Sisto that 

 Raphael painted the celebrated Sistine Madonna, 

 sold in 1754 by the monks to Frederick Augustus 

 of Saxony. Among the other buildings are the 

 I'iilax/o Farnese (1558), once a sumptuous edifice, 

 but since 1800 in use as barracks; the communal 

 palace ( 1281 ), its lower story built of marble 

 and the upper of brick ; the palace of justice, 

 and others. A couple of miles to the east of 

 the city is the theological seminary founded by 

 Cardinal Alberoni. The municipal library con- 

 tains 120,0(10 volumes. The principal square is 

 adorned with colossal bronze equestrian statues of 

 Alessandro and Ranuccio Farnese. Manufactures 

 of silks, cottons, pottery, hats, &c. are carried on. 

 The more notable facts in the history of Piaeen/.a 

 have l>een its capture by the Gauls in 200 and by 

 Totila in 546, the meeting here of two church 

 councils in 1095 and 1132, its active zeal as a 

 member of the Lombard League in the 12th 

 century, the sac-king of it by Francesco Sforza 

 in 1447, and its union with I'arma (q.v.). Pop. 

 (1897) 35,500. The )>rrii><-<- has an area of 950 

 square miles and a [nip. of '230,000. 



Pia Mater. See BRAIN. 



Piana Dei CJreri, a town of Sicily, 10 miles 

 S\V. of Palermo. It was the chief Albanian 

 colony in Sicily in the 15th century. 



Pianoforte (Hal. puma, 'soft,' and forte, 

 ' loud ' ), a stringed musical instrument, played by 

 keys, developed out of the clavichord and Harpsi- 

 chord (q.v.), from which the pianoforte ditlers 

 principally in the introduction of hammers, to put 

 the strings in vibration, connected with the keys by 

 a mechanism that enables the player to modify at will 

 the intensity of the sounds ; whence the name of the 

 instrument. The invention of the pianoforte must 

 l>e accredited to Bartolomeo Cristofali, a native of 

 Padua, who produced his instrument in 1714. Other 

 claimants to the honour are a German organist of the 

 name of Schroter, and Marius, a French harpsi- 



