The dominant physical characteristics of the four classes of wool referred to are :-For mountain wools, strength of fibre and in some cases a free intermixture of coarse and fine fibres ; for lustre wools, that lustre which the manufacturer can develop in his lustre fabrics ; for demi-lustre wools, either an approach to a lustre type or more frequently a loftiness in handle well suiting the type of wool for the coarser hosiery fabrics. For down wools, a fineness combined with loftiness which specially fits these wools for the finer hosiery styles; and for merino wools, a special fibre fineness with plasticity of handle which enables the spinner to pro duce the finest possible wool yarns and the manufacturer to obtain a superb "handle" in his fabrics.
The other distinguishing qualities of good wool are uniformity and strength of fibre with freedom from tender or weak portions in its length, a condition which not unfrequently arises from ill health in the sheep, or is due to violent climatic changes. In ill bred wool there may also be found intermingled "kemps" or dead hairs-straight, coarse, dull fibres which show conspicuously among the wool, and become even more prominent in the manu factured and dyed goods, as they will not take dye.
as it comes from the sheep's back is in anything but a pure form. The follow ing analyses carried out at Leeds university (Barker and Wilson) give an idea of the problem facing the wool-scourer who, receiving wool "in the grease," is expected to turn it out clean with a moisture content of about i6% in the weight of the clean dried wool.
4 - "tZ "-§
0 71 2 4' 3
.4. <) e. p
of wool 0 4.,. cq 3 8
CI t,
c...) i'::: cn 4., CI, 0 !).) P., % % % % % % % Lincoln (washed) • 73'3
2.06 1.63 99.48 Merino . . 45.0 9.0 13.0 24.0 4.0 6.o IoI•o Corriedale . 54-o 13-0 10.0 12.0 5.9 6.o 100.9 Southdown . 5o.o ii•o 16.o io.o 5.2 8.0 100.2 Burry . . 6 2 .o
9.3 10.0 4.5 4.6 102.9 A careful analysis of typical wools (Speakman) usefully indi cates the percentages on the weights of the clean dry wool of "wool fat" and "suint" usually present.
The variations here in evidence are remarkable and well illus trate the difficulties with which the wool-scourer has to contend. It is usual now to recover the wool fat which is placed on the market as "lanoline," but it is not usual to attempt to recover the potash salts.
to Dr. Bowman, the chemical composition of the cell structure of the average wool fibre is Carbon 5o.8Hydrogen 7.2 Nitrogen 18-5 Oxygen 21.2
Sulphur 2-3 Ioo-o It is said to be a most complex body of which the probable formula is C42H157N5S015.
If wool is burnt, it largely resolves itself into ammonia gas whence it derives its characteristic odour-and carbon "beads" or "remains," which serve to distinguish wool from cotton, which, upon being burnt, does not smoulder but burns with a flash and leaves no beads. For further particulars on the organic nature of the wool-fibre see FIBRES.
bulk of the wool of commerce comes into the market in the form of fleece wool, the product of a single year's growth, cut from the body of the living animal. The first and finest clip, called lambs' wool, may be taken from the young sheep at about the age of eight months. When the animal is not shorn till it attains the age of twelve or fourteen months the wool is known as hogg or hogget, and, like lambs' wool, is fine and tapers to a point. All subsequently cut fleeces are known as wether wool, and usually possess relatively somewhat less value than the first clip. Fleece wool as it comes into the market is "in the grease," that is, unwashed, and with all the dirt, etc., present ; or it is received as "washed" wool, the washing being done as a preliminary to the sheep-shearing ; or, in some few cases, it is scoured and is consequently stated as "scoured." Skin wool is that which is obtained from sheep which have either died or have been killed. Typical skin wool is that which has been removed by a sweating process or by painting with sulphide.
there is abundance of water and other conveniences it is the practice to wash sheep previous to shearing, and such wool comes onto the market as washed. Where running streams exist, the sheep are penned by the side of the water, and taken one by one and held in the stream while they are washed, one man holding and the other washing. Sheep washing appliances are now largely employed, the arrangement consisting of a pen into which the sheep are driven and subjected to a strong spray of water either hot or cold, which soaks the fleece and softens the dirt. This done, they are caused to swim along a tank which narrows towards the exit, and just as they pass out of the pen they are caught and subjected to a strong douche of pure water. They should then be kept on grass land free from straw, sand, etc., so that the wool may be sheared free from vegetable matter, etc. After a few days the wool of a washed sheep is sufficiently dry for shearing or clipping.