PIS 



PLA 



sumcs a bluish cast, and if the shep- 

 herd have not the means of changing 

 the pasture, all those affected will fall 

 in the course of a month." 



PINION. A small wheel playing 

 in the teeth of a larger one. It is 

 sometimes only a spindle or arbor. 



PINK. The genus Dianlhus ; per- 

 ennial flowering plants, propagated 

 readily by layering. 



PINK ROOT. Spiffelia Marilandi- 

 ca. Carolina pink, a handsome per- 

 ennial, growing about the borders of 

 woods in the South ; the roots are 

 used in infusion as a powerful vermi- 

 fuge ; the dose for children of three 

 years is 10 grains of the powder: in 

 very large quantities it proves a dan- 

 gerous narcotic. 



PINNACLE. A square or polyg- 

 onal pillar rising above a building, and 

 terminating in an ornamental pyra- 

 mid. 



PINNATE. Leaves with separate 

 leaflets arranged along the midrib, or 

 petiole : some are doubly pinnate. 



PINNATIFID. Imperfectly pin- 

 nate. In this case the leaflets are 

 not distinct, but a portion of tiie lam- 

 ina runs along the central petiole. 

 Cut-leafed. 



PLNT. The eighth part of a gallon ; 

 half a quart. 



PIP. A disease of poultry, attend- 

 ed with the formation of a tough 

 membrane at the tip of the tongue, 

 which hinders feeding ; it is cured by 

 pulling off the membrane and wash- 

 ing the part with salt : the cause is 

 said to be bad water and food, which 

 should be changed. 



PIPE. A wine measure of rather 

 uncertain capacity — 105 imperial, or 

 126 wine gallons. 



PIPE CLAY. White clay, disin- 

 tegrated feldspar found in primitive re- 

 gions, with which the white smoking 

 pipe and coarse pottery are made. 



PIPERIN. A white, crystalline, 

 inactive alkaloid, obtained from black 

 pepper. 



PISE. In building, a wall con- 

 structed of stiffearth or clay, carried 

 up in moulds, and rammed down as 

 the work is carried up. The ex- 

 pression, building en pise, is common. 



PISOLITE. Native limestone, 

 moulded into grains like peas. 



PISTACHIO, or PISTACHIA 

 NUTS. Pistac/na vera. A turpen- 

 tine-tree, a native of Syria ; the nuts 

 are the size of small filberts, of a 

 sweet taste and pleasant flavour re- 

 sembling almonds. 



PISTIL, PISTILLUM. The cen- 

 tral organ of flowers ; it is divided 

 into an ovarium, or lowest part, a 

 style, and stio^ma, which last is the 

 uppermost surface, and receives the 

 fertilizing pollen. It is called the 

 female organ, because flowers in 

 which it is absent are barren. Pis- 

 tils are made of one or more carpels, 

 the styles of which unite. Flowers 

 with pistils only are termed pistil- 

 late. 



PISTON. A short cylinder of 

 wood or metal, which fits e.\actly the 

 cavity of a pump or barrel, and is 

 worked up and down in it alternate- 

 ly. Two sorts of pistons are used 

 in pumps : one hollow, witli a valve, 

 used in the sucking pump ; and the 

 other solid, which is employed in the 

 forcing pump. 



PITCH. The substance that re- 

 mains after boiling or distilling tar ; 

 it is used as a coarse paint when 

 warmed. 



PITCH OF A ROOF. Its incli- 

 nation to a level plane. 



PITHING. The operation of kill- 

 ing animals suddenly and without 

 loss of blood, by driving a knife into 

 the spinal marrow : tliis is done by 

 directing the knife to the space be- 

 tween the first and second vertebra, 

 or rack bones. 



PITTACALL. A blue substance 

 obtained from oil of tar. 



PITUITARY GLAND. The pi- 

 neal gland, situated in the base of 

 the brain. 



PITUITARY ME.MBR.\NE, 

 SCHNEIDERI AN .M E M B R A N E. 

 The mucous membrane of the nos- 

 trils. 



PITYRIASIS, DANDRUFF. A 

 scurfy disease of the skin. 



PIVOT. The extremity of an axle 

 which revolves in a socket or hole. 



PLACENTA. The after-birth. A 



579 



