DEW-BETTING, Oft KOEA.GE. 149 



of water is required. The bottom ought to be paved, 

 with a slope towards the place where the water is let out. 

 There ought, indeed, to be a double outlet, one at the 

 surface and one at the bottom, either to be used as occa- 

 sion may render convenient. The sides should slope 

 witli so steep an inclination as to allow the workpeople 

 to approach with ease, and not be obliged to enter the 

 water, in order to arrange or alter anything in the hemp- 

 heap, as will be necessarily wanted from time to time. 

 The sides, if not built of stone or brick- work, should be 

 covered with cement of sufficient thickness. The mud 

 taken every year out of the bottom of the steeping-plaee, 

 makes excellent manure." 



DEW-EETTING, Oli EOEAGE. 



A month is the time ordinarily required for dew-retting 

 hemp in the open air. It is impossible to make sure 

 that during this interval, there will be no showers, 

 tempests, or hail, and above all that the hemp will not be 

 attacked by insects. High winds may ruffle it, or blow 

 it aw r ay ; heavy rains may dissolve unequally as well as 

 too rapidly the gummy principle contained in the bark. 

 Hemp, which at the beginning of its air-retting, is exposed 

 to frequent or heavy showers, is apt to turn black, and 

 mostly remains of a permanently dark grey colour. The 

 fibres adhere together more firmly than in hemp which is 

 retted without exposure to rain, nearly in the same way 

 as the hairs of a painter's varnish-brush when it is dry. 

 Twisting the hairs of such a brush, causes the resin of 

 the varnish to fall off in a state of powder. Now, ifc 

 ought never to be forgotten that the best performed 

 retting still leaves a considerable amount of resin in the 

 hemp ; and we cannot too strongly insist on the fact, that 

 that is the principal obstacle to the bleaching of thread 

 and cloth. Such, too, is the origin of the annoying dust 

 (as inflammable as powdered colophone, or fiddler's rosin) 

 which fills the air of the workshops in which the beating 

 and scutching of the fibre is performed, and which by 



