MARKING COLOUR FOR LINEN, &CV %& 



will take place very fpeediiy by bleaching with the oxigenated 

 alkaline muriatic ley, the pieces of which the ends have 

 been plunged for a few minutes in the alkaline as before pre- 

 fer i bed. Thefe marks of the brown oxide of manganefe 

 refill not only all the bleaching materials, and all acids of a 

 requisite force, but likewife the moft complicated procefs of 

 manufacture of calico printing. 



Se&ion II. 

 If the acetic acid had not a much ftronger affinity with The acetate ot\ 

 manganefe than it has with iron, and if it difengaged it- "o^teufed with* 

 ielf as readily from the acetate of manganefe as it does out the fame 

 from the acetic folution of iron by evaporation and drying, ^aHtTsmore 

 we mould be able to procure indeliable marks in the molt coftly itmuft be 

 fimple manner, by depofiting the oxide of manganefe on re J efted » 

 piece goods by means of the acetic acid, and afterwards 

 iimply leaving the oxide to the attraction and faturation of 

 oxigen from the air. The acetic folution of manganefe is very 

 readily obtained by mixing a proper quantity of acetate of 

 lead in a folution of fulphate of manganefe. But as .this 

 acetic folution affords no advantage in marking piece goods 

 beyond thofe of the fulphate of manganefe, and as it requires 

 precifely the fame management as that defcribed in the Iaft 

 fection, and it is likewife more expenfive, it deferves to be 

 rejected. 



Scaion III. 

 Two ounces of fulphate of magnefia diflblved in eight Sulphate of 

 ounces of the acetic folution of iron, concentrated to the point ma "^ ane [ e . wIth 



' acetate or iron 



indicated by twenty degrees, afford when thickened with treated as before, 



one fortieth part of gum adraquack, a deep yellow liquor Itdr ^ smore 



which becomes more and more brown, when treated ab- 



folutely in the fame manner as defcribed in the firft paragraph. 



The acetic folution does not, however, afford any other 



advantage but that of caufing the marks to dry a little more 



fpeediiy ; for the oxide of iron diflblves in acids accordingly, 



as it is oxigenated. I give the preference to gun>adragant 



for thickening colours, to other gums and to ftarch, becaufe 



thefe fubftances weaken the colours too much , if however, 



there mould be any objection to gum-adragan in Coarfe goods, 



Itarch may be then ufed. '■' ' f v ■' 



Vol. XII.— November, JS05, P Scftion IV. 



