[ 425 ]

trials must undoubtedly have been made, before successcould have been attained to. But experience has abun-dantly shetvn that the case is otherwise j that the fenugreekseed, fleawort seed, cummin seed, coloquintida, cocculusindus, buckthorn berries, agaric, nitre, sal ammoniac, salgem, litharge, antimony, black-lead, orpiment, corrosivesublimate, white arsenic, realgar, several of which areadded again and again in different parts of the operation,are entirely inessential to the dye, and contribute rather todo harm than good. Mr. Macquer himself suspects thatsome of these ingredients are unnecessary; and he hassubjoined a process followed in the manufacturies of Toursand G6nes, from which we may fairly conclude that theyare all so ; and that a fine black may be dyed on silk in assimple a method as on wool or woollen cloth, the silk re-quiring only a greater quantity of the ingredients, and agreater number of dippings in the black liquor. Theprocess is as follows.

The silk, washed with soap as above directed, is steepedin a decoction of one third its weight of Aleppo or bluegalls, or half its weight of the weaker white galls of Sicilyand Romania, and afterwards washed with water: everytwelve ounces are reduced by the cleansing to nine, whichought to be increased by the galling to eleven and notmore. The dying liquor, for a hundred pounds of silk,is prepared by boiling twenty pounds of galls in asufficient quantity of water (about a hundred and twentysix gallons) and adding to this decoction, after beingsettled and drawn off from the sediment, two pounds anda half of English vitriol, twelve pounds of iron filings,and twenty pounds of the gum of the cherry or plumtree: that the gum may dissolve the more readily, it isput into a large copper cullender, immersed in the hotliquor, and stirred and worked from time to time with a

wooden