PLA 



U-ined, by a variety of experiments by M. 

 Jurine, of Geneva. A very large surplus 

 of carbon, however, slill enters the animal 

 sw-rn. through the medium of the lac- 

 teals, and continues to circulate with tfi 

 chvle, OP the blood, till it reaches t! 

 lungs. Here, again, a considerable poi- 

 tion of carbon is perpetually parted with 

 upon every expiration, in the same form 

 of carbonic gas, in consequence ot i 

 union with a' part of the oxygen intro- 

 duced into the lungs with every returning 

 inspiration; as is sufficiently established 

 by the experiments of Mr. Davy and other 

 celebrated chemists; while the L excess, 

 thai vet remains, is earned oft by the 

 skin, in consequence of its contact with 

 atmo'pheric air: a fact put beyond all 

 doubt by the experiments and observa- 

 tions of M. Jurine, although, on a super- 

 ficial view, opposed by a few experiments 

 of M Inirenhouz ; and obvious to every 

 one, from the well-known circumstance, 

 thai the purest linen, upon the pmest 

 skin, in the purest atmosphere, soon b 

 comes discoloured. In this way, then, 

 and by this triple co-operation ot the sto- 

 mach.the lungs, and the skin, vegetable 

 matter, in its conversion into animal, part, 

 with the whole of its excess of carbon. 

 Its deficiency of azote becomes supplied 

 in a twofold method. First, at the lungs ; 

 also, by the process of respiration ; tor 

 v-e uniformly find, and the experiments ol 

 Dr. Priestley and Mr. Davy are tutly c< 

 elusive upon this subject, that a largei 

 portion of azote is inhaled upon every in- 

 spiration, than is returned by every suc- 

 ceeding expiration; in consequence i 

 vvhich,She portion retained m the lungs 

 must enter into the system, in the sa 

 manner as the retained oxygen, and pel- 

 haps in conjunction with it ; while, m 

 unFson with this action of the lungs he 

 skin also absorbs a considerable quantity 

 of aiote, and thus completes the supply 

 that is necessary for the animahzation 

 vegetable food ; evincing, hereby, a d< 

 bie consent of action in these two organs, 

 and giving us some insight into the mod 

 by which insects and worms, which are 

 t6tally destitute of lungs, are capable ot 

 employing the skin as a substitute for 

 lumrsbv breathing through certain spi- 

 racles introduced into the skin for this 

 pu po'se%r merely through the common 

 Sores of the skin, without any such addition- 

 al mechanism Itisbythis mode, also that 

 res.rxti..n takes place through the whole 

 vegetable world, offering us another in- 

 stance of resemblance to many parts of the 

 animal ; in consequence of which, insects, 



PLA 



worms, and the leaves of vegetal, 

 equally perish, by being smeared over 

 with oil, or any other viscous fluid, that 

 obstructs their cutaneous orifices. 



" But to complete the great circle 

 universal action, and to preserve the im- 

 portant balance of nature in a state ot 

 equipoise, it is necessary, also, to inquire 

 by what means animal matter is recon- 

 verted into vegetable ; so as to afford to 

 plants the same basis of nutriment which 

 plants have previously afforded to ani- 

 mals." 



The process of putrefaction is shown to 

 be that principle, which is to be regarded 

 as a most important link in the great chain 

 of universal life and harmony. See Good s 

 Oration. 



Corallines, madrepores, millepores, and 

 sponges, were formerly considered as los- 

 sil bodies ; but the experiments of Count 

 Marsigli evinced, that they are endued 

 with life, and led him to class them with 

 the maritime plants And the observa- 

 tions of Ellis, Jussieu, and Peysonel, haye 

 since raised them to the rank ot animals. 

 The detection of error in long established 

 opinions, concerning one branch of natu- 

 ral knowledge, justifies the suspicion 01 

 its existence in others, which are nearly 

 allied to it. And it wjll appear, from th 

 prosecution of an enquiry into the i 

 stincts, spontaneity, and self-moving pow- 

 er of vegetables, that the suspicion is not 

 without foundation. 



PLANTAGO, in botany, plantain, a ge- 

 nus of the Tetrandria Monogynia class 

 and order. Natural order of Plantagmes, 

 Jussieu. Essential character : calyx four- 

 cleft; corolla four-cleft, with the border 

 reflex ; stamina very long ; capsule two- 

 celled, cut transversely. There are thirty- 

 eight species. These plants, having lit 

 tie beauty, are rarely cultivated, except 

 in botanic gardens. 



PLASHING of quickset hedges, an ope 

 ration very necessary, to promote the 

 growth and continuance ot old hedges 

 It is performed in this manner : the old 

 stubs must be cut oft; &c. within two or 

 three inches of the ground, and the best 

 and longest of the middle sized shoots 

 must be left to lay down Some of the 

 strongest of these must also be left to an- 

 swer the purpose of stakes. These are to 

 be cut oft' to the height at which the hedge 

 is intended to be left; and they are to 

 stand at ten feet distance one from an- 

 other : when there are not proper shoots 

 for these at the due distances, their places 

 must be supplied with common stakes ot 

 dead wood. The hedge is to be first 



