4x?
The immersion should take place as fast as possible, for the moment the hot water pene-trates the mordanted cloth, the acetic acid quits it; and, therefore, if the immersion wasMade slowly or one ply after another, the acid as well as the uncombined mordant becomefree, would spread their influence, and would have time to dissolve the aluminous sub-salts now combined with the cloth; whence inequalities and impoverishment of the colorswould ensue.
It is difficult to determine the number of pieces which may be passed through a givenquantity of dung and water. This depends upon the state of the mordants, whetherJl' e y are strong or acid, and on the quantity of the surface covered with the figures,fhe number varies usually from 20 to 60 pieces, for from 240 to 300 gallons of waterand 6 gallons of dung. The time of the immersion varies with the concentration of theMordants, and the nature of their thickening. The temperature must be regulated by* ne same circumstances; for starch or flour paste a much warmer bath is needed thanor gum. The heat varies usually from 130° to 212° F. When the printing is heavyand the thickening is starch or flour, tfie goods are usually twice dunged, with two wash-ln gs between the two dungs. A strong acid mordant is more difficult to dung and to'yasli than a neutral mordant, especially when it is to receive the madder dye. Some-Mtes a little chalk is added to the bath, when the goods have been padded in an acidor dant. Too much dung is injurious to weak mordants, as well as to pinks. It hasIso been remarked that a mordant when neutralized does not produce as brilliant tints,Specially yellows. The latter are obtained of a finer shade when, instead of dunging,j V are exposed for an hour in a stream of water, provided its temperature is not tooIn winter they are passed through a slightly chalky water, then washed at the® e lj and dyed in quercitron or weld.
ist Ver y able an< I learned memoir upon this subject, by M. Penot, Professor of Chem-i ni> - v > appeared in the Bulletin of the Society of Mulhausen, in October, 1834, with an^eaious commentary upon it, under the title of a Report by M. Camille Kcechlin, in~L rct >, 1835.
of x P er >cnce has proved that dunging is one of the most important steps in the processg e (. a Mo printing, a nd that if it be not well performed the dyeing is good for nothing.** We can assign its peculiar function to the dung in this case, we must know itss 0tn t ;Slti °n. E resb cow’s dung is commonly neutral when tested by litmus paper; butan itna] meS . ^ * s sb = bl '5 r alkaline, owing, probably, to some peculiarity in the food of the
1 ®att 6 t0ta ' constituents of 100 parts of cow dung are as follows: Water, 69-58; bitter
sweet substance, 0-93; chlorophylle, 0-28 ; albumine, 0-63 ; muriate of’ su lP ba t e °f potash, 0-05; sulphate of lime, 0-25 ; carbonate of lime, 0-24;”. e of lime, 0-46; carbonate of iron, 0-09; woody fibre, 26-39; silica, 0-14;
° s Phati
'{• o-h;
luhi^ Un =* n " calicoes
sa iubh
the excess of uncombined mordant is in part attracted by the
affinity ? atters °f the cow’s dung, and forms an insoluble precipitate, which has nu° r tbe especially in presence of the insoluble part of the dung, which
*8 alumina. The most important part which that insoluble matter plays,
th e b Ze ^ 6 eXcess the mordants, in proportion as they are dissolved by the waterthe denn ■ 5 ant ^ thus to render their reaction upon the cloth impossible. It is only in^efo Ul hj SUe 5 therefore, that the matters carried off from the cloth by the dung are to
^f^hlin ascribes the action of cow dung chiefly to its albuminous con-Y the hot mbln * n " w ith the alumina and iron, of the acetates of these bases dissolvedp test 0 f] V f ter ' 0f tbe batb ’ The ac ^ s consequently set free, soon become evident bye hher bv m p S paper > a ^ er a ^ ew pi eces are passed through, and require to be got ridhx the bas^ * eS ^ ° r ^ ac ^‘ n £ ehalk to the old one. The dung thus serves alsoPower on^h* 11 ^ c ^ otb > w hen used in moderation. It exercises likewise a disoxyda-^aiatter. e lron mor flant, and restores it to a state more fit to combine with color-
jjett 0llj Ji nen ’ Tr.; Fathered , Germ.) is the art of impregnating wool, silk,
o r age . to Wch th r ’-fiK Ski ns > With co ^ ors not removable by washing, or the ordinaryRaiment , t s y? & ri a 1 ; rous bo( *ies are exposed when worked up into articles of furnitureOcular dyes m!5 * c °asider the general principles of the art, referring for the' st ancpo in t j. P e ^ u '' lai ] treatment of the stuffs to be dyed, to the different tinctorialie Phabetical places: such as cochineal, indicro. mnddpr. fee.
Part;.
v. ta »ces _ _ ..
is a"lto"pTti P i 1 . at>eti J aI ? laces i such as cochineal, indigo, madder, &e,
" r hii.K Ce an acquaint 1 & C ■ em ' ca * Process, and requires for its due explanation andc hem- re S u late their anca Wltb tbe properties of the elementary bodies, and the lawsv i e ^‘ cal arts, have , ° mblnatl °ns. It i s true that many operations of this, as of otherM the ' Vere er >tcrtaineU J? ractlsel * from the most ancient times, long before any justr udest and most r fin nature °f tbe changes that took place. Mankind, equallyonned state, have always sought to gratify the love of distinction27 e