349 



PEARL WHITE. 



PEAT. 



360 



agreements with the people who hire out the boats are conducted 

 much in the same manner. They contract either to receive a certain 

 sum for the use of their boats, or pay the chief farmer of the banks a 

 certain sum for permission to fish on their own account. Some of 

 those who pursue the latter plan are very successful and become rich, 

 while others are great losers by the speculation. The spirit of gambling 

 is more openly exhibited, for oyster lotteries are carried on to a great 

 extent, and they consist of purchasing a quantity of the oysters un- 

 opened, and running the chance of either finding or not finding pearls 

 in them. As soon as the oysters are taken out of the boats, they are 

 carried by the different people to whom they belong and placed in 

 holes or pits dug in the ground to the depth of about 2 feet, or in 

 small square places cleared and fenced round for the purpose, each 

 person having his own separate division. Mats are spread below them 

 to prevent the oysters from touching the earth, and here they are left 

 to die and rot. As soon as they have passed through a state of putre- 

 faction and have become dry, they are easily opened without any 

 danger of injuring the pearls. On the shell being opened, the oyster 

 nutely examined for the pearls ; it is usual even to boil the oyster, 

 as the pearl, though commonly found in the shell, is not unfrequently 

 contained in the body of the fish itself. 



Captain Percival, in his account of Ceylon, states that in preparing 

 the pearls, particularly in drilling and stringing them, the natives are 

 wonderfully expert. A machine made of wood, and of a shape re- 

 sembling an obtuse inverted cone, about six inches in length and four 

 in breadth, is supported upon three feet, each twelve inches long. In 

 the upper flat surface of this machine holes or pita are formed to 

 receive the larger pearls, the smaller ones being beat in with a little 

 wooden hammer. The drilling instruments are spindles of various 

 sizes, according to that of the pearls ; they are turned round in a 

 wooden head by means of a bow handle, to which they are attached. 

 The pearls being placed in the holes, and the point of the spindle 

 adjusted to them, the workman presses on the wooden head of the 

 machine with his left hand, while his right is employed in turning 

 round the bow handle. During the process of drilling, he occasionally 

 moistens the pearl by dipping the little finger of his right hand in a 

 cocoa-nut filled with water, which is placed by him for that purpose ; 

 this he does with a. dexterity and quickness which scarcely impede the 

 operation, and can only be acquired by much practice. The Cingalese 

 have also a variety of other instruments both for cutting and drilling 

 the pearls. To clean, round, and polish them to the state in which 

 we see them, a powder, made of the pearls themselves, is employed. 

 These different operations in preparing the pearls occupy a great num- 

 ber of the natives in various parts of the island. In the black town or 

 pettah of Columbo in particular, many of them may every day be seen 

 at this work. 



The Chinese adopt a singular mode of procuring pearls by artificial 

 means, that of compelling or inducing the fish to make them. They 

 force open the shell of a large river mussel, and put in a small bit of 

 wood or metal The fish becomes irritated, and covers the intruding 

 substance with a pearly deposit. Very often small clay figures are 

 thus introduced, representing Buddha in the sitting posture in which 

 that image is moat frequently pourtrayed. It has been stated that no 

 leas than 5000 families are engaged in this singular branch of industry 

 near Ningpo. Some of these pearl-covered figures of Buddha are to be 

 seen in the South Kensington Museum. 



The beautiful substance called (somewhat expressively) mother of 

 pearl, is the hard, lustrous, brilliant internal layer of shells, especially 

 oyster shells, and more particularly the pearl oyster. In English 

 oysters this substance is too thin to be workable for manufacturing 

 purposes ; but the oysters of the eastern seas yield it of considerable 

 thickness. The brilliant hues which distinguish mother of pearl do 

 not depend upon the nature of the substance, but on an exquisitely 

 fine series of furrows upon the surface, which shed a brilliant reflection 

 of colours according to the angle at which the light falls on them. 

 Much care is required in working this delicate substance ; but it may 

 be cut by saws, files, and drills, with the corrosive aid of sulphuric or 

 muriatic aoid. It is polished by colcothar of vitriol. In all those 

 ornamental manufactures where pearl is said to be used for flat sur- 

 faces, such as inlaying, mosaics, buttons, knife-handles, Ac., it is not 

 real pearl, but mother of pearl, that is employed ; and the quantity 

 now consumed in England, especially at the manufacturing establish- 

 ments of Birmingham and Sheffield, is very large. An instance has 

 been recorded of a ship arriving at London from Panama with more 

 than two miUvm pearl shells. 



PEAK!, \VH ITK. [BigmjTH, Nitrate /.] 



PEAT : Economical Via. Peat is a substance of vegetable origin, 

 found wherever the soil has been long soaked with water which has no 

 outlet and does not completely evaporate by the heat of the sun. 

 When dried peat is examined, it is found to consist of roots and fibres 

 in every stage of decomposition, from the natural wood to the com- 

 pletely black vegetable mould. From the nature of its formation 

 under the surface of water, it acquires a portion of tannin, which has 

 the property of preserving animal and vegetable matter from decom- 

 position. Hence large branches and trunks of trees are found 

 imbedded in peat, which have no mark of decomposition, except what 

 may have taken place before the wood was completely immersed in 

 the peat. Peat contains all the element* of the richest manure, 



and may by an easy process be converted into humus : for this purpose 

 the agency of alkalies is the moat effectual. If the tannin be decom- 

 posed, decomposition of the vegetable fibre will go on, and soluble 

 humus will be formed. When peat is newly dug up, if caxistic lime be 

 added to it before it is dry, the moisture of the peat slakes the lime, 

 which acts on the gallic acid in the peat and neutralises- it. If this 

 mixture be then excited to fermentation by the addition of animal 

 matter, such as urine or dung, oxygen is absorbed and carbonic acid 

 evolved ; and the residue is converted into an excellent manure, con- 

 taining much soluble humus. The same may be effected more slowly 

 by mixing peat with clay or marl, and allowing the mixture to remain 

 exposed to the atmosphere for a considerable time, frequently turning 

 it. But nothing accelerates this process like the addition of putrescent 

 animal matter, which acts as a ferment and greatly hastens the decom- 

 position. The soils for which peat forms the best manure are the 

 chalky and clayey. Sand has too little tenacity; it lets the gases 

 produced by the decomposition escape, instead of attracting them, as 

 clay and chalk do, and preventing their escape. 



The burning of peat destroys the vegetable matter and leaves the 

 earths and salts behind. They are accordingly very strong stimulants 

 to vegetation, especially that of clovers and herbaceous plants, of 

 which the leaves and stems are the most valuable parts. If the soil 

 is well furnished with vegetable matter, and capable of bringing an 

 abundance of seed to perfection, it may be very useful to apply stimu- 

 lating manures, such as peat ashes, to increase the verdure ; but on 

 poor soils destitute of humus, the increase of the stems and leaves does 

 not ensure a proportionate increase of seed. Hence it is often 

 remarked that soot, potash, saltpetre, and similar substances produce a 

 deceitful growth, giving a rank green leaf, which is not succeeded by a 

 heavy ear; but, on the contrary, the produce in seed is rather 

 diminished than increased by the use of the manure. Whenever a 

 stimulating manure is used, the soil should be naturally rich, or enrich- 

 ing manure should be applied at the same time. 



Where a great extent of peat-moss renders the improvement of it 

 desirable, there are various ways in which it may be reclaimed. In 

 some places the peat has been removed, and the loam which lay below 

 it was found of a very fertile nature. This could only be done on the 

 banks of rivers, into which the peat was floated by means of small 

 canals dug through it, and communicating with the river. In all other 

 cases the mode adopted has been that of draining and consolidating. 

 In draining a peat-moss the water must not be let off too rapidly, for 

 in that case the surface may become so loose and dry, that no vegeta- 

 tion can take place in it. If the water is drained off so as to leave 

 two feet of peat dry above its level, this is all that is required for a 

 beginning. The best improvement, and the most rapid, is produced 

 by bringing sand or gravel in sufficient quantity to cover the surface 

 with two or three inches of it. This will make a beginning of a soil, 

 in which potatoes may be planted. At first the surface will not bear 

 the wheels of a cart nor the tread of a horse ; but in a short time a 

 solid crust will be formed, which will increase in strength and thick- 

 new as cultivation advances. There are many fine pastures in Scotland 

 which once were brown peat-mosses, on which it would have been 

 dangerous for a man to walk, but which now bear heavy oxen, and seem 

 as solid as any pasture on a clay subsoil. Manuring and liming are the 

 most effective operations in bringing about this great improvement. 

 Potatoes and oata are usually the first crop on reclaimed peat-mosses. 

 It is long before they become capable of bearing wheat ; nor is this 

 crop to be recommended at any time, unless there be a good depth of 

 soil formed over the peat. Laying down to grass as soon as a certain 

 degree of improvement has been made, and depasturing with sheep at 

 first and cattle afterwards, tend more than any other means to con- 

 solidate the surface and deepen the mould, which gradually increases 

 by the decomposition of the tannin in the peat. 



Great attention has been paid within the last few years to the ques- 

 tion how far peat can be practically applied in the arts, thereby 

 rendering a double service clearing bog-land for agricultural purposes, 

 and making good use of the substance taken from it. As Ireland con- 

 tains 3,000,000 acres of bog, the inquiry really becomes an important 

 one. Several years ago, a patent was obtained by Mr. Williams, man- 

 aging director of the Dublin Steam Navigation Company, for compres- 

 sing peat into a dense mass, so as to resemble coal. The process is as 

 follows : Immediately after being dug, the peat is triturated under 

 revolving edge-wheels faced with iron plates perforated all over the 

 surface, and is forced by the pressure through these apertures, till it 

 becomes a species of pap, which is freed from the greater part of its 

 moisture by a hydraulic press. It is then dried, and converted into 

 coke in the same manner as is done with pit coal. The factitious coal 

 of Mr. Williams is made by incorporating pitch or rosin melted in a 

 cauldron with as much of the peat-charcoal ground to powder as will 

 form a tough doughy mass, which is then moulded into bricks. 



The use of peat for fuel is too well known to require notice ; but it 

 may be interesting to know how peat fuel is made in Holland, where 

 it cannot be dug out of the solid moss but is brought up in the form 

 of mud from a considerable depth under water. It is raised by means 

 of small strong nets, fixed by an iron ring to a long pole, in the man- 

 ner in which canals are cleared of mud. This liquid peat is brought 

 in boats to a place prepared for its manufacture, which has been 

 levelled as a brick-yard usually is. The soft mud is spread over this 



