PAR 



PAR 



and camphor with oil of anise seed ; 

 an anodyne to allay pain. 



PARELLA. Lecanora parella. A 

 lichen of Europe, used as a dye, atid 

 similar to archil. 



PARENCHYMA. The cellular 

 substance of vegetables or animals. 



PARGASITE. A kind of horn- 

 blend {actinolyte). 



PARGET. The plaster of lime, 

 hair, cow dung, and water used in 

 coating the flue of a chimnev. 



PARHELION. The appearance 

 of two or more suns from the misty 

 state of the air. Faraselcn<t are sev- 

 eral moons seen from the same cause. 



PARIETAL. In botany, any or- 

 gan which grows from the sides of 

 another is said to be parietal. The 

 parietal hones, in zoology, are those at 

 the sides of the skull, wliich together 

 form the arch. 



PARING AND BURNING. '^ This 

 operation consists in cutting a thin 

 slice from the surface of land which 

 is overgrown with grass, heath, fern, 

 or any other plants which form a 

 sward by the matting together of 

 their roots. The sods are allowed to 

 dry in tlie sun to a certain degree, 

 after which they are arranged in 

 heaps, and burned slowly, without 

 flame or violent heat. The result is 

 a mixture of burned earth, charred 

 vegetable fibre, and the ashes of that 

 part which is entirely consumed. 



" The object of this operation is two- 

 fold : first, to kill insects and destroy 

 useless or no.xious weeds completely ; 

 and, secondly, to obtain a powerful 

 manure, impregnated with alkaline 

 salts and carbonaceous matter, which 

 experience has shown to be a very 

 powerful promoter of vegetation. 



" The instruments by which this 

 is effected are either a common 

 plough with a very flat share, which 

 may be used when the surface is very 

 level without being encumbered with 

 stone or large roots, as in low moist 

 meadows, or, in most other cases, a 

 paring-iron, which is used by hand. 

 The cross-bar of this instrument is 

 held with both hands, and the upper 

 parts of the thighs, being protected 

 by two small slips of board, push the 



A A A 



\ instrument into the ground, so as to 

 cut a slice of the required thickness, 

 which is then turned over by moving 

 the cross-handle. The labour is se- 



1 vere, and a good workman can 

 scarcely pare more than one sixth of 



i an acre in a day. 



I " Paring and burning the surface 



! is an almost invariable preliminary 

 in the converting of waste lands to 

 tillage ; and where these lands are in 

 a state of nature, overrun with wild 

 plants which cannot be easily brought 

 to decay by simply burying them in 

 the ground, burning is the readiest 

 and most efTectual mode of destroy- 

 ing them. In this case the practice 



\ is universally recommended and ap- 

 proved of. 



" But it is not only in the reclaim- 



I ing of waste lands, and bringing them 

 into cultivation, that paring and burn- 

 ing the surface is practised. The 

 fertility produced by the ashes, which 

 is proved by the luxuriance of the ve- 

 getation in the first crop, has induced 

 many to repeat this process so often 

 as materially to exhaust the soil, and 



I induce partial sterility. Hence the 

 practice has been recommended on 

 the one hand and strongly reprobated 

 on the other. 



" ^^'hen we come to apply to the 

 subject the test of experience, and 

 reason correctly on the facts which 

 are presented to us by the abettors 

 of the practice and its adversaries, 

 we shall find that the advantages and 

 disadvantages arise chiefly from the 

 circumstances under which the oper- 

 ation is carried on. But it may be 

 necessary to an impartial examina- 

 tion of the subject, to inquire into the 

 changes produced on the substances 

 subjected to the process of burning, 

 when it is done with due precautions. 

 " In burning vegetable matter in an 

 open fire, the whole of the carbon is 

 converted into carbonic acid and flies 

 off, leaving only some light ashes, 

 containing the earthy matter and the 

 salts which the fire could not dissi- 

 pate. These are, no doubt, very pow- 

 erful agents in promoting vegetation, 

 when they are added to any soil ; but 

 they are obtained at a very great ex- 



i>.')3 



