PERINEUM 



PERIODICALS 



51 



Perinaenm, the floor of the human pelvis 

 The anterior portion, situated in front of the anus 

 is called the true perineum, or urethral portion of 



IB penmeum; the posterior portion is called the 

 anal portion or ischio-rectal region. 



Period and Periodicity. One of the most 



iking features of the ordinary phenomena of 

 nature is their tendency to recur and repeat them- 

 selves apparently indefinitely ; and in general this 

 repetition takes place at successive and practically 

 equal intervals of time. The day, the month, the 

 year are familiar examples of such periods, corre- 

 sponding respectively to the earth's rotation the 

 moons progression through its phases, and the 

 earths changes of distance from the sun. As a 

 factor in human life the year is practically traced 



t by the climatic changes that accompany its 

 progress, but strictly speaking it is the period 



ermmed by the recurring configurations of earth 

 ami sun. Many periodic phenomena of importance. 

 such as eclipses, transits, occupations, depend like 

 the moons phases on the configurations of three 

 Ixx ' 



ing a book complete in itself, may, strictly speak- 

 i ng ' I1 ?f., de / !CI ? bed , a 8 a Periodical, from the fames 

 to Whttakers Almanac and the Post-office Direc- 

 tory The use of the term is, however, restricted 

 mary conversation to magazines and reviews 

 appearing not less frequently than once a quarter 

 and not more frequently than twice a month.' 

 Weeklies, at least in Great Britain, have with a 

 few exceptions ceased to be regarded as periodicals. 

 As we have no foitmghtlies, our periodicals may 

 >e said to be practically reduced to monthlies and 

 fufir 



ons o ree 



; and long before Newton's law of gravita- 

 tion gave the key to the cosmic universe the 



c unverse e 



pen.Mls or some of these had been discovered. See 

 <m<nNOLOOY( with its variou s cycles-the metonic 

 19 years, the Cahppic of 76 years, &c.), CYCLE 

 DAY, I-.rui-sKs, YEAR, &c. 



When we look into th,- minute mechanism of 

 nature we find here also the same prominence 

 attached to periodic qualities. Sound and light 

 '"ns.M physically of a vibratory or oscillatory 



otmri or some ,rt ; and to the accurate time 

 periodicity of these motions we trace our sensa- 

 tions of harmony in music and colour. In certain 

 r-sp.., -K however, the periodk-ity i imperfect 



:h period not being an exact reproduction of ita 

 predecessor. Thus, a tuning fork or pianoforte- 

 string vibrating freely in air rapidly loses its vibra- 

 tory character, ami its motion steadily decays- 

 and yet, judged by the pitch, the frequency w 

 time periodicity remains the same throughout In 



se and similar cases Viscosity (q.v.) ultimately 

 ransforms the original vibratory energy into heat 

 (see EEKV ). Heat itself is bafereTto be some 

 kind of vibratory energy of the molecules; and 

 the metraMope demonstrate* that intense heat is 



lamly anociated with definite periodic motions 

 e to rays of corresponding periodicity (see 



ortCTRUM ). 



Passing now to the other extreme, we find 

 chiefly in astronomy, instances of long periods 

 ome of which have not been completed within 

 historic times bm ,,f which the evidence is incon- 

 trovertible The Precession (q.v.) of the equi- 

 oxes and the slow changes in the eccentricities 

 inclinations of nlanetary orbits may be rnen- 

 ione.1 by way of ilfustration. The geologist also 

 has found evidence of periodic changes in the 

 matic conditions of the earth (see GLACIAL 

 FnuOD, ll,KisT,K-KNK). Generally periodicity 

 involve the idea of time; but We may have 

 Periodic qualities depending on position or on 

 ""I'irig A very good example of this is the 

 ! law of modern chemistry (see ATOMIC 



IHLOKY; also WAVE). 



Life is as full of periodic phenomena as inani- 

 e nature ; but the increasing complexity of 

 conditions makes the periodicity still less perfect, 

 In the beating f the heart, in the alternation of 

 HOD* and sleeping, of hunger and satiety we 

 examples of vital actions with a distinct 

 periodic character. 



Periodicals. Everything is a periodical that 



1 Pi'l.ishe<l periodically. Every publication that 



' published more than once is necessarily publish,.,! 



Periodically. Therefore every publication, except- 



The refusal of the English-speaking world to 

 tolerate fortnightly publications is as remarkable 

 w it is unmistakable. In France and Italy and 

 Belgium the fortnightly is regarded as the natural 

 form of the high-class periodical. Outside these 

 countries the fortnightly is practically unknown. 

 Neither in Great Britain, nor in Greater Britain, 

 has it been found possible to acclimatise the fort- 

 ightly. In Russia, in Germany, in Scandinavia, 

 in Spain and Portugal the periodicals are 

 monthly. As if to remind the world of the con- 

 stitutional incapacity of the English race to take 

 literature in bimonthly instalments, the Fort- 

 nightly Review is published monthly, but religiously 

 announces on every cover tha't the Issue of the 15th 

 is suspended. 



The number of periodicals is almost numberless. 

 1 here are 332 monthlies in Italy alone, of which 

 it a moderate computation, 300 are read by no one 

 outside Italy, and by probably fewer than 300 sub- 

 Kriben within the peninsula. But the number of 

 rriodica s of general interest that are worth calling 

 Tiodicals are comparatively few. In Italy for 

 instance, there are hardly more than three which 

 e outside world ever heard of. In France there 

 are not more than four or five. Differerit countries 

 excel in different departments. For pure literature 

 and criticism the Rente des Deux Mondes has the 

 st place. For illustration America leads easily 

 distancing all rivals with the Century, Scribner's 

 //////*; while in the second rank, although 

 HI ahead of foreign competitors, with one exeep 

 Bon, come the Cosmopolitan and the New England 

 Maya***. The only exception is the German 

 magazine, Velhagen vnd Klasing's Nene Monats- 

 ^ i- ,'"', eneral interest and solidity combined 

 the Lnglish quarterlies and monthly miscellanies 

 rank fact, although they are hard pressed by the 

 Nouvelle Remie, the North American Review, the 

 arum, and the Arena. For bulk the Russians 

 lurpass all the magazinists and reviewers of the 

 orld. The Russian monthly contains about three 

 times as much printed matter as the Nineteenth 

 Century In proportion to its size Belgium leads 

 world in the multiplicity of its periodicals- 

 but then prosperity is in an inverse proportion to 

 their numbers. There is only one Portuguese 

 monthly procurable in London. 



The genesis of the periodical can be traced back 

 for centuries, but the earlier publications of the 

 kind bear about as much resemblance to the 

 magazines and reviews of to-day that the eohip- 

 pus bears to the winner of last year's Derby. The 

 evolution of the modern magazine is usually traced 

 bac-k to the Philosophical Transactions of the Rova* 

 Society, which began to appear in 1665, but the 

 true progenitor of our monthly miscellanies were 

 the pamphlets which were spawned in such num 



. ^....,~... ,- vjiBwavu in SUCH num- 



bers in the heat of the revolutionary ferment of the 

 17th century. There was no regular periodicity in 

 their appearance. Pamphleteers wrote as the 

 spirit moved them, but their intermittent pro- 

 ductions, in everything excepting the regularity of 

 their appearance and the fact that each appeared 

 singly instead of being stitched together with a 

 dozen others, correspond very closely to the 



