The fine silk of _Nankin_ requires no whitening. _On aluming silk._ We have treated of this before at the commencement of the third chapter, but a few more observations may be useful. The silk being first well washed and beetled, and the hanks tied loose so that every thread may take alike, should be turned and re-turned in the alum liquor and worked, cooled in it, at intervals, from morning till night, afterwards taken out, beetled, and rinsed. The above proportion of alum will do for a hundred and fifty pounds of silk, before you need replenish it; when this is necessary add twenty-five pounds more of alum, as at first directed in Chapter III., and so continue to replenish it till it gets a bad smell. When this is the case you may dip for browns, maroons, &c.; and afterwards throw the liquor away; the trough is then to be rinsed for a fresh liquor. Remember always to alum _cold_ or you will spoil the lustre of the silk. _Skein silk for_ YELLOW. This is to be boiled with about twenty pounds of soap for every hundred pounds of silk. When boiled it is to be washed and alumed, and again washed, dressed, and put on the rod, seven or eight ounces to a rod, and then dipped and re-turned in the yellow liquor, in the proportion of two pounds of weld to one pound of silk. The liquor is not to be hotter than the hand can bear while the silk is in it. The silk, when in the vessel for dyeing, should cause the liquor to float within two inches of the edge. The silk must be taken out and the liquor strengthened, if the pattern is to be very full; when full enough, one pound of pearl-ash for every twenty pounds of silk must be dissolved in some warm water; about a quarter of this liquor is put into the dye bath: take the silk out while you put in the liquor, stir the mixture well. Put in the silk and work it, turning and re-turning it as at first. After seven or eight re-turns, one of the hanks is to be taken out, wrung, and tried at the peg, and, if sufficiently full and bright, all is well; if not enough so, some more pearl-ash liquor must be added, and the silk worked as before, till the shade required is obtained. For _jonquil_ it may be necessary to add some annatto when you put in the pearl-ash. To make the light shades, such as _canary_ or _lemon_, perfectly white, they must be boiled with thirty pounds of soap to a hundred of silk; and if these be not _azured_ to be dyed, they must have a little of the blue vat, and a little of the weld liquor in water, (the whole mixture being as hot, but no hotter than the hand will bear,) and the silk ready on rods, must be quickly worked through and out. For deeper lemons the same process must be used as for the fuller yellows; only less weld, and twenty pounds of soap will do for a hundred pounds of silk in whitening it.