POIl 



POS 



through a portal, and going 1 down with 

 great timidity into a darker region, where 

 lie is received by a beautiful female, who 

 stretches forth her hand to help him: 

 between her knees is a large and playful 

 serpent. She sits with her feet towards 

 an aged figure, having 1 one foot sunk into 

 the earth, and the other raised on a co- 

 lumn, with his chin resting on his hand. 

 Above the female figure is a Cupid pre- 

 ceding the first figure, and beckoning 

 him to advance. This first figure holds 

 a cloak or garment, which he seems 

 anxious to bring with him, but which ad- 

 heres to the side of the portal through 

 which he has passed. In this compart- 

 ment there are two trees, one of which 

 bends over the female figure, and the 

 other over the aged one. On the bottom 

 of the vase there is another figure, on a 

 larger scale than the one we have already 

 mentioned, but not so well finished nor 

 so elevated. This figure points with its 

 finger to its mouth. The dress appears 

 to be curious and cumbersome, and above 

 there is the foliage of a tree. On the 

 head of the figure there is a Phrygian 

 cap ; it is not easy to say whether this 

 figure be male or female. On the han- 

 dles of the vase are represented two 

 aged heads, with the ears of a quadruped, 

 and from the middle of the forehead rises 

 a kind of tree without leaves : these 

 figures are, in all probability, mere orna- 

 ments, and have no connection with the 

 Test of the figures, or the story repre- 

 sented on the vase. 



PORTLANDIA, in botany, so named 

 in honour of the Duchess of Portland s a 

 genus of the Pentandria Monogynia class 

 and order. Natural order of Rubiacese, 

 Jussieu. Essential character : corolla club, 

 funnel-shaped; anthers longitudinal; cap- 

 sule five cornered, obtuse, two-celled, 

 two-valved, many-seeded, crowned with 

 A five-leaved calyx. There are four spe- 

 cies. 



PORTMANTEAU, a cloak bag of 

 cloth, leather, &c. in which the cloak, 

 linen, and other habiliments of travellers 

 are disposed and laid on the horse's crup- 

 per. The same name is also given to a 

 piece of joiners' work fastened to the 

 wall in a wardrobe, armoury, See. proper 

 for the hanging on of cloaks, hats, &c. 



PORTRAIT, PotruTKAiT, or Poua- 

 TRAITUIIE, in painting, the representa- 

 tion of a person, and especially of a face 

 done from the life. In this sense we use 

 the term portrait-painting, in contradis- 

 tinction to history-painting, where a re- 

 semblance of person is usually disregard- 



ed. Portraits, when as large as the life, 

 are usually painted in oil-colours ; some- 

 times they are painted in miniature with 

 water-colours, crayons, pastils, &c. See 



POUT UL AC A, in botany, purslane, a 

 genus of the Dodecandria Monogynia 

 class and order. Natural order of Succu- 

 lentse. Portulaceae, Jussieu. Essential cha- 

 racter : calyx bifid; corolla five-petalled ; 

 capsule one-celled, cut round, or three- 

 valved. There are twelve species; of 

 which P. oleracea, garden purslane, is an 

 annual herbaceous plant, with a round, 

 procumbent, succulent stem ; diffused 

 branches, often throwing out fibres at the 

 joints ; leaves wedge-shaped, oblong, 

 blunt, fleshy, sessile, clustered, espe- 

 cially at the ends of the branches : 

 flowers sessile, corollas yellow, spread- 

 ing ; it is a native of both Indies, China, 

 and Japan. 



PORT ULAC ARIA, in botany, a genus 

 of the Pentandria Trigynia class and or- 

 der. Essential character : calyx two-leav- 

 ed ; petals five ; seed one, three-sided 

 and winged. There is but one species, 

 viz. P. afra, a native of Africa. 



POSITION, or the rule of false Posr- 

 TIOX, otherwise called the rule of FALSE- 

 HOOD, in arithmetic, is a rule so called, 

 because, in calculating 1 on several false 

 numbers taken at random, as if they were 

 the true ones, and from the differences 

 found therein, the number sought is de- 

 termined. This rule is either single or 

 double. Single position is when there 

 happens in the proposition some parti- 

 tion of numbers into parts proportional, 

 in which case the question may be re- 

 solved, at one operation, by this rule. 

 Imagine a number at pleasure, and work 

 therewith according to the tenor of the 

 question, as if it were the true number -, 

 and what proportion there is between 

 the false conclusion and the false propor- 

 tion, such proportion the g'iven number 

 has to the number sought. Therefore- 

 the number found by argumentation shal! 

 be the first term of the rule of three ; 

 the second number supposed, the second 

 term ; and the given number, the third- 

 Or the result is to be regulated by this 

 proportion, viz. As the total arising from 

 the error to the true total, so is the sup- 

 posed] part to the true one. Example, 

 A, B, and C, designing to buy a quantity 

 of lead to the value of 140/. agree that B 

 shall pay as much again as A, and C as 

 much again as B ; what then must each 

 pay ? 



Now suppose A to pay Wl. then B 



