PURPLES 



PUSEY 



497 



the flight is very vigorous. The male flies especi- 

 ally high, and 

 will perch on 

 lofty trees. The 

 caterpillar is 

 green and feeds 

 on sallow. 



Purples. 



See WHEAT. 



Purple 

 Wood, or 



PURPLE HEART, 

 the heartwood of 

 Copaifera pubi- 

 flora and C. 

 Purple Emperor. bracteata, a very 



handsome wood 



of a rich plum colour. The trees producing it are 

 natives of British Guiana, and its chief use in 

 England has been for making ramrods for guns. 



Pnr'pnra, a genus of marine Gasteropods, 

 from some species of which (e.g. P. patula), as 

 well as from Murex, the famous Tynan purple dye 

 was derived. P. lapillus (the E)og Whelk) is 

 common on most British coasts, and from it also 

 the dye is procurable. See WHELK. 



Pnrpnra, or THE PITRPLES, is a malady which 

 is often erroneously placed amongst the diseases of 

 the skin. It is in reality a blood disease, and is 

 characterised by the appearance of small round 

 spots, of a deep purple colour, which are seen first 

 and most abundantly on the legs, and afterwards 

 extend to the arms and trunk. They are accom- 

 panied by no local pain, are not effaced by pressure 

 (being due to a drop of blood extra vasated beneath 

 the cuticle or in the structure of the skin itself), 

 do not rise alxivc the surrounding surface, and are 

 sometimes intermixed with livid patches resem- 

 bling bruises ; and, before disappearing, both the 

 round spots and the patches undergo the same 

 change of colour which a bruise undergoes. These 

 spots are not peculiar to the skin, but occasionally 

 occur upon internal surfaces and in the tissues of 

 viscera. Passive hiemorrhages from the mucous 

 membranes frequently accompany the external 

 symptoms. There is usually much debility, and 

 often a great tendency to faintness. The duration 

 of the disease varies from a few days to a year or 

 more. Slight cases are devoid of danger, and even 

 the hajmorrhagic cases usually recover, unless the 

 bleeding has l>een excessive or the blood has been 

 extravasated into a vital organ. 



Precisely similar appearances occur in the course 

 of other diseases, especially scurvy, severe anaemia, 

 scarlet fever, and smallpox. But the name pur- 

 para should be restricted to the cases in which no 

 such disease is discoverable. 



The causes of purpura are obscure. The treat- 

 ment which succeeds best varies in different cases, 

 but the main indication always is to correct the 

 condition of the blood. Arsenic, turpentine, 

 acetate of lead, gallic acid are the drugs which 

 are generally most beneficial ; rest in bed, lif,'ht 

 diet, and laxatives .are desirable at the commence- 

 ment. When there is reason to believe that the 

 disease is dependent upon depressing influences a 

 nutritious diet, tonics, and stimulants are required; 

 but chalybeates should he avoided. If the hneinor- 

 rhage proceeds from accessible parts, local measures, 

 such as the employment of ice or strong astringents, 

 should also be had recourse to. 



Purser, the name formerly given to the officer 

 in the navy who had the charge and issue of the 

 provisions, slops, soap, tobacco, &c., and who 

 also kept the ship's books ; the title was one of the 

 oldest in the service, but the holders of it for long 

 only ranked as warrant-officers, and their duties 

 396 



and responsibilities were in many respects very ill- 

 deh'ned. In the old war-days they were looked 

 upon with great dislike by the seamen, as they 

 were credited with enriching themselves at the 

 expense of the men, and unquestionably the oppor- 

 tunities for sharp practice in their duties were con- 

 siderable, as also for making money by methods 

 which were not always legitimate ; much of this, 

 however, was due to the laxity of the system of 

 victualling and of keeping the ship's accounts in 

 those days. In 1844 this branch of the service was 

 completely reorganised, paymaster being substi- 

 tuted for the title purser ; and the officers compos- 

 ing it are now drawn from a much higher class 

 than formerly, coming generally from the same 

 station in life as the combatant officers. See PAY- 

 MASTERS. 



I'll r si il lie (Portulaca), a genus of plants of 

 the natural order Portulacese, having a bifid calyx, 

 four or six petals, eight or sixteen stamens, and a 

 capsule dividing around the middle. Common 

 Purslane (P. oleracea) grows in cultivated and 

 waste grounds on the seashore in almost all 

 tropical and subtropical parts of the world. It is 

 cultivated as a pot-herb. It is a short-lived annual, 

 with spreading and rather procumbent stems, and 

 obovate fleshy leaves, which, as well as the young 

 shoots, are frequently used in salads. The young 

 and tender shoots are pickled in France like gher- 

 kins. Purslane is not so common in British gar- 

 dens as it once was. Some species of Portulaca, 

 such as P. grandiflora, of which there are several 

 brilliant varieties, and P. gilliesii, are choice half- 

 hardy annuals occasionally cultivated in British 

 gardens. They are reared in hotbeds in spring 

 and planted out in the flower-garden in the end of 

 May, or they are grown in pots exclusively for the 

 purpose of decorating the greenhouse. 



Pursuivant. See HERALD. 



Pus is a well-known product of inflammation, 

 and occurs as a thick yellow creamy fluid, differing 

 from all other morbid exudations in containing a 

 large number of corpuscles, having a soft and fatty 

 feeling when rubbed l>etween the fingers, a peculiar 

 odour, usually an alkaline reaction, and a specific 

 gravity of aliont r03'2. Like the blood, it consists 

 of certain definite microscopic elements, and of an 

 intercellular fluid or serum in which they swim. 



Of microscopic elements we have ( 1 ) the pus- 

 corpuscles, which, both in their microscopical and 

 chemical relations, seem to be identical with the 

 lymph-corpuscles, or colourless blood-cells ; in 

 diameter they range from '004 to "005 of a line, 

 and each corpuscle consists of a cell-wall, which 

 often appears granular, of viscid transparent con- 

 tents, and of one or more nuclei, which can be 

 rendered much more apparent by the addition of 

 acetic acid. The other elements are (2) molecular 

 granules and (3) fat-globules. The serum of pus 

 is perfectly clear, of a slightly yellow colour, closely 

 resembling blood-serum, and coagulates on heating 

 into a thick white mass. 



The chemical constituents of pus are water 

 (varying from 769 to 907 in 1000 parts), albumen 

 (from 44 to 180), fats (from 9 to 25), extractive 

 matter (from 19 to 29), and inorganic salts (from 

 6 to 13), in addition to which niucin, pyin, glycin, 

 nrea, &c. are occasionally present. Of the inor- 

 ganic or mineral constituents the soluble salts are 

 to the insoluble in the ratio of 8 to 1, and the 

 chloride of sodium (the chief of the soluble salts) 

 is three times as abundant as in the serum of the 

 blood. The mode of formation of pus is described 

 in the article SUPPURATION. 



Piisev, EDWARD BOUVEKIE, was born in the 

 year 1800 at Pusey in Berkshire. He was descended 

 from a family of Flemish refugees ; his father was 



