n 



PLINTH. 



PI,OIK:H. 



known, if the disease do not apontaneonsly make iU appearance, spare 

 no pains to produce it So great is the prejudice in favour of Plica 

 entertained by the lower order of Poles, who regard it as affording a 

 certain security from all other sickness and misfortunes, that they will 

 through their whole Urea endure the inconvenience and misery of 

 carrying about huge masses of filthy stinking hair many feet in length, 

 rather than submit to the removal of it, which U neoecsary for their 

 relief. 



The hair of persons affected with Plira Polotica has been carefully 

 examined under the microscope, and Gttnsberg and Von Walther have 

 both described the cells of fungi belonging to the genus Trichophyton. 

 The parasite as described by Uunsberg consists of articulated fila- 

 ment* surrounded by innumerable spores of very minute size. The 

 changes in the hair produced by this parasite consist in the thickening 

 of the root of the blur, a spindle-like enlargement of the longitudinal 

 cylinder of the channel of the hair, through the constant piling up of 

 new masses of fungi in it, in the splitting and parting of single hair 

 flbres, which gives at hut to the hair the appearance of a brush, or of 

 a hedgehog skin, at the point through which the spores of the fungus 

 pass. The epithelium or cells of the hair arc very much condensed, 

 and the hair cylinder frequently altogether disappears. In the 

 adhesive mass are found a great many huge epithelial cells with small 

 granular bodies, resembling the exudation corpuscles of inflammation. 

 Von Walther attempted to inoculate Plica Polonica, but did not 

 succeed. 



Herr von Studrienski, a Russian, has recently written on the Plica, 

 and endeavoured to show that it was only an intense form of the 

 natural condition of moulting. This view however U not supported 

 by the facts of the case, and no one con doubt iU specially morbid 

 nature, after such researches as those of Von Walther and Giinaberg. 



The only treatment which is known to be constantly beneficial is 

 the removal of the ban-, and strict cleanliness ; other means must be 

 decided in each case by the general state of the patient's health. The 

 popular notion entertained in Poland, that dangerous diseases will 

 follow the cutting of the hair, is entirely without foundation. 



(Kuchenmeister on Animal and Vegetable Pararitei, translated by 

 Lankester, 1847.) 



ri.l.VTH. [COLUMN.] 



PLOMBAGIN. A bitter non-azotised principle of unknown com- 

 position, contained in the root of thpftfmbago europoea. It crystallises 

 in orange-yellow needles of au^fliiiiminl saccharine taste, volatilises 

 by heat without cbange^efrtsalightly soluble in cold water, more so 

 in hot, and readily soJafalcohol and ether. Alkalies communicate to 

 th<^ aqueous solujjpfa fine cherry-red colour. 



^^^^ the plough is an instrument of the highest 



J0t$fky is apparent both from the oldest writings that we possess 

 mRd from the existing monuments of Egypt We might exercise our 

 imagination in supposing a probable origin of the plough in the branch 

 of a tree dragged along the ground, in which the stump of a smaller 

 branch made furrows as it went on. It seems indeed probable that 

 some accidental circumstance first suggested this mode of stirring the 

 earth to prepare it for receiving the seed. 



The oldest forms of the plough of which we have any description in 

 ancient authors, or which are represented on monuments and corns, 

 are very simple : a mere wedge, with a crooked handle to guide it, and 

 a short beam by which it was drawn, form the whole instrument The 

 light Hindu plough, now in use in many parts of India, seems to differ 

 little from the old model. 



Before we enter into any details it may be as well that we describe 

 the different essential parts of a plough, by the names which are usually 

 given to them. 



The body of the plough is that part to which all the other parts are 

 attached. The bottom of it u called the tote, or Jade, to the fore part 

 of which is affixed the point, or dare ; the hind part of the sole i 

 called the krtl. The beam, which advances forward from the body, 

 srrves to keep the plough in its proper direction, and to the end of it 

 are attached the oxen or horses which are employed to draw it Fixed 

 in the beam, in a vertical position, before the point of the share, with 

 iU point a little forward, is the coulter, which serves to cut a vertical 

 action hi the ground, while the point of the share, expanding into a 

 Jin, separates a slice by a horizontal cut from the subsoil or solid ground 

 under it The mnnld-bonrd or turn -furrow, is placed ul.!i.|u<-ly behind 

 the fin, to the right or left, in order to push sside and turn over the 

 slice of earth which the coulter and share have cut off: it thus leaves 

 a regular furrow wherever the plough has passed, which furrow is 

 intended to be filled up by the slice cut off from the land by the side 

 of it, when the plough returns. The stilU or handles, of which there 

 may be either one or two, as is thought more convenient, direct the 

 plough by keeping it in the line required and at a regular depth in the 

 ground. The single (tilt appears to be the moat ancient form. 



Wheels are a modern invention in comparison with the other parU. 

 'They support the end of the beam, and prevent it from going too deep 

 into the ground while the plough in going on. The greatest improve- 

 ments introduced into modern plough* are in the shape of the mould- 

 board, or turn-furrow, of which we shall take particular notice, and 

 the contrivances for regulating the line of draught, so as to make the 

 plough go at an equal depth, and cut off a regular slice of equal breadth, 



without any great force being applied by the ploughman who holds 

 UM stilts. 



The Hindu plough consists of a slight beam, often without any 

 coulter, a narrow share, and a corresponding stilt The whole is of 

 wood, slightly pointed with iron. It U so light that a man can readily 

 carry it upon bis shoulder. When it is at work it is usually drawn 

 by a small buffalo, and sometimes by a man or a woman. Thin in>tru- 

 mi-lit U intruded merely to make a shallow furrow in a very light -il, 

 or in the mud produced by irrigation where rice is cultivated. It does 

 not act as our ploughs do, nor does it turn over a regular furrow, 

 but it acts more like one of the tines, or tooth, of some of our more 

 complicated instruments called cultivators or grubbers, with which Un- 

 earth U stirred without being turned over. 



The Chinese plough resembles the Hiudu in its simplicity. The 

 earth is turned over by holding the instrument obliquely, and much 

 depends on the art of the ploughman, in whose hands it is like a stout 

 shovel pulled through the ground by a horse or an ox. The sole is not 

 straight, but rounded, like the bottom of a boat The work done by 

 this instrument is not unlike the furrow drawn in the sand at the 

 bottom of the sea when a ship drags her anchor. 



The ploughs in use in different countries in Europe underwent little 

 change for many centuries ; it is only lately that any attempt has been 

 made to vary the old forma. 



The Roman plough, such as is described by Virgil in the ' Georgia ' 

 (i. 174), is still used in many parts of France, under the name of Araire 

 Remain. It consists of a beam (temo), a body (Ituru), a share (roiiicr), 

 and a handle or stilt (ttira). The office of the turn-furrow is per- 

 formed by two pieces of wood about six inches long projecting ob- 

 liquely upwards, and very properly called teeth (dentalia) K T (Pig. 1). 

 The sole of the plough A B has two pieces of wood c o and D u fixed to 

 it on each side, forming an acute angle with it, in which the teeth are 

 inserted. This exactly answers the description of Virgil, " Duplici 

 aptantur dentalia dorao " (the teeth are fitted to the double bock). 



Fig. 1. 



These teeth help to push aside the earth to the right and left, and the 

 instrument resembles what is called a moulding plough, which is used 

 in throwing the soil aside againat young plants growing in rows, as 

 turnips, potatoes, &c. A chain or pole connected with the end of the 

 beam was hooked to the middle of the yoke on the neck of the oxen, 

 and thus the plough went on making parallel furrows, so near to each 

 other that the preceding furrow was partially filled with the earth which 

 the dentalia pushed aside. The point was in the shape of the head of 

 a lance. This plough might suffice in light mellow soils, which had 

 been long in cultivation, and had more the texture of garden mould 

 than of stubborn clay. 



The small double mould-board plough, common in other parts of 

 France, is evidently taken from this. The teeth not being sufficiently 

 strong, a slanting board was substituted on each side, and wheels were 

 added, to diminish the labour of the ploughman. The stilt remained 

 the same at the place where it U attached to the plough, but higher up 

 it was divided into two, like a fork, for the convenience of holding it 

 with both hands. This plough acts exactly like the other, but it is 

 stronger and better adapted for heavier laud. Neither of them goes 

 much deeper than four or five inches, leaving shallow parallel ridges, 

 in which the seed falls, and is buried by light wooden harrows, which 

 are drawn over the land after sowing. This is an imperfect tillage, 

 the bottoms of the furrows being only partially stirred. The broad 

 flat share, and the single mould-board which turns the earth com- 

 pletely over, after lifting it up, is a for more effectual instrument, and 

 has been adopted wherever agriculture has mode any improvement 

 This plough more nearly imitates the digging with a spade ; ami the 

 more perfect the imitations, the better is the work. 



The mould-board of a modern plough is either fixed on one side, or 

 made so as to be shifted from one side to the other. In the first cose half 

 the furrow-slices lie on one side and half on 111" other, and there U of 

 necessity a double furrow where they join. When it in duirablc that 

 the surface should be quite flat, and the furrow-slices all in one direc- 

 tion, the mould-board must be shifted at every turn, and a plough 

 which admits of this is called a turn-wrest plough. 



It is evident that the mould-board of a turn-wrest plough must be so 

 constructed as to act with either side uppermost ; it can therefore have 

 only a very slight convexity to push over the slice cut off by the coulter 

 and share; and a considerable force is lost by the obliquity of tlm 

 action in doing so. The share of this plough is pointed like a lance, or 

 presents a flat edge like a broad chisel, according as the soil is light or 

 heavy. The point of the coulter is placed in line with that t 

 the point which is nearest to the unploughcd land, and this ia <ln< i., 

 means of a piece of wood A B (/'/>/. 2), which presses it against one side 

 or the other of the mortice in which it is place* in the beam c o, by 

 changing the position of the pieces A B to the other side of the projec- 



