PERCH 



6053 



PERCUSSION CAP 



As a debater he proved himself an 

 able opponent of Fox. On Pitt's re- 

 tirement in 1801 Perceval became 

 solicitor-general and attorney-gen- 

 eral in 1802. He was leader of the 

 House after Pitt's death in 1806, 

 and became chancellor of the ex- 

 chequer in 1807, to which office was 

 added that of first lord of the trea- 

 sury in Sept., 1809. Perceval was 

 assassinated in the lobby of the 

 House of Commons on May 11, 

 1812, by Bellingham, a crazy bank- 

 rupt. See Lives, Sir S. Walpole, 

 1874 ; P. Treherne, 1909. 



Perch (Percafluviatilis). Fresh- 

 water fish of the order Acantho- 

 pterygii. It is a native of Britain, 



Perch, a fish common in European 

 and North Asiatic rivers 



the greater part of Europe, and 

 much of N. Asia. It is distinct in 

 form, having a somewhat oblong 

 body with the back humped above 

 the pectoral fins. There are two 

 dorsal fins, of which the anterior 

 is the more conspicuous, both 

 from its superior size and its strong, 

 sharp-pointed rays. The back is 

 coloured a dark ashy green, paling 

 along the sides to a whitish tint 

 below. At intervals along the 

 sides is a series of broad vertical 

 bands of dark brown ; whilst the 

 ventral, anal, and tail fins are some 

 tint of red. Ordinarily the perch 

 attains a length from 9 to 12 ins., 

 and a weight of 2-3 Ib. See 

 Climbing Perch ; Fish. 



Perch (Lat. pertica, a pole). 

 Measure of length, an alternative 

 n ame for the rod or pole. See Rod. 



Perche. One of the old pro- 

 vinces of France, lacer incorporated 

 in the prov. of Maine. It was 

 bounded N. by Normandy, W. by 

 Maine, S. by Orleanais, and E. by 

 the lle-de-France. It now forms 

 the depts. of Orne and Eure-et- 

 Loire. It gives its name to the 

 Percheron (q.v.). 



Perche, COL DE LA. Pass of the 

 Pyrenees. It lies on the frontiers 

 of France and Spain, beyond Mont- 

 Louis, and between the valleys of 

 the Tet and the Segre. The Span- 

 iards were defeated here by the 

 French in 1793. Its height is 

 5,175ft. 



Perched Blocks. In geology, 

 name given to isolated masses of 

 rocks which have been transported 

 from their original source of for- 



mation by glacial action. Such 

 rocks, often also called erratic 

 blocks, are typical in Alpine glacial 

 districts, and are found scattered 

 all over Europe and in parts of 

 Great Britain. 



Percheron. French breed of 

 heavy draught horse, named from 

 the province of Perche. Of a grey 

 colour and standing about 16 

 hands, it has a large but neat 

 head, magnificent neck, and clean 

 limbs. It has been well described 

 as a trotting cart-horse. Before the 

 advent of motor traction, the Lon- 

 don omnibus was conspicuously 

 in charge of the percheron. See 

 Horse, colour 

 plate. 



Perchloric 

 Acid (HC10 4 ). 

 Colourless, f u m- 

 ing, volatile liquid 

 obtained by the 

 action of sul- 

 phuric acid on 

 potassium p e r- 

 chlorate. When a 

 few drops of the 



public school was perhaps the great 

 work of his life. President of Trinity 

 College, Oxford, 1878-87, he then 

 became headmaster of Rugby, 

 1887-95. In the latter year he 

 was made bishop of Hereford, and 

 he remained there until his death, 

 Dec. 3, 1918. Percival was an 

 advanced Liberal in lay and 

 ecclesiastical politics and in the- 

 ology. His biography was under- 

 taken in 1921 by William Temple, 

 bishop of Manchester. See Bishop 

 Percival, E. M. Oakley, 1919. 



Percolation. Process of de- 

 priving vegetable matter of its 

 soluble constituents, by allowing 



>e 



Alexandre Percin, 

 French soldier 



acid are placed on paper or wood, 

 they at once set them on fire. 



Percin, ALEXANDRE (b. 1846). 

 French soldier. Born at Nancy, and 

 educated at the Eeole Poly tech 

 n i q u e, he 

 joined the ar- 

 t i 1 1 e r y, and 

 served in the 

 campaign o f 

 1870, during 

 which he was 

 twice wound- 

 ed. Captain at 

 the age of 24, 

 he afterwards 

 held many 



important appointments, both mili- 

 tary and civil, including that of 

 inspector-general of firing instruc- 

 tion in the field artillery. On the 

 outbreak of the Great War, he 

 commanded the first region at 

 Lille. Percin was mainly instru- 

 mental in perfecting the use of the 

 " 75 " gun. 



Percival, JOHN (1834-1918). 

 British prelate and schoolmaster. 

 Born at Brough, Westmorland, 

 son of a yeo- 

 man, he was 

 e d u cated at 

 Appleby and 

 Queen's Col- 

 lege, Oxford, 

 of which he 

 became a 

 fellow. He 

 was ordained 

 in 1860, and 

 became a ' 

 master at 

 Rugby. In 1862 

 the first headmaster of Clifton 

 College, and the creation of thia 



Percolation applied in the manufacture of soda. See text 



a solvent to trickle slowly through. 

 The method is used in pharmacy for 

 exhausting vegetable drugs of their 

 active constituents, and the prin- 

 ciple is employed in preparing 

 coffee as a beverage. The vessel 

 used is called a percolator. The 

 figure shows how the principle of 

 percolation is applied in the manu- 

 facture of soda in Shanks' vats. 

 Ball soda or caliche, a, a, a, a, rests 

 on a layer of ashes on the per- 

 forated false bottom, b, of the 

 percolator. Fresh water is supplied 

 through pipes, c, while d is a drain 

 for weak liquor or waste water. 

 The water percolates from vat to 

 vat and issues at e as strong liquor. 

 Percussion. Musical term 

 applied to the sounding of a dis- 

 cord after preparation and before 

 x resolution. Per- 



n '^^ i I 





John Percival, 

 British prelate 



flM oil Jb Fry 



he was made 



cussion i n s t r u- 

 ments are those 

 in which sound 

 c/1 ^ issetupby 



being struck either with sticks(gong, 

 and all drums), with hammers 

 (pianoforte, dulcimer, glocken- 

 spiel, xylophone, etc. ), with a steel 

 rod (triangle), with clappers (bells), 

 or, being in pairs, by being struck 

 against one another (cymbals, 

 castanets, ete. ). Most of these have 

 definite pitch of varying compass, 

 but the gong, the bass and side 

 drums, the tambourine, the triangle, 

 the cymbals, and the castanets 

 are merely noise-producers. 



Percussion Cap. Small case of 

 explosive, which may be ignited 

 by the shock of a blow and is used 

 to convey ignition to the propel- 

 lant charge of a gun or ritlo. Ful- 

 minate of mercury was discovered 



