DYE 
fustic, and galls, to which copperas is ad- 
ded. 
For marone, and similar colours, sannders 
and galls are employed ; and sometimes a 
browning with the addition of logwood. 
These colours may be made to incline to 
crimson or purple, by adding a small quan- 
tity of cochineal or madder. A little tartar 
gives brightness to the colour. With a 
mixture of galls, fustic, and logwood, some 
madder, and a little alum, hazel colours are 
produced. 
Of dyeing Silk dark mixed colours. 
Silk may be dyed a violet purple, without 
a blue ground, by preparing it with a mor- 
dant of two ounces of alum, one ounce of 
solution of tin, and half an ounce of muriatic 
acid, to each pound ; steeping it twelve 
hours in a mixture of one part of galls dis- 
solved in white wine, with three parts of 
water ; and then, after wringing, dyeing it 
in a bath composed with two ounces of 
cochineal and a small quantity of iron liquor, 
till the intended shade is given. Madder 
may be used in the same way. 
Colours resembling that of bricks may be 
produced, by immersing silk in an annotta 
bath, after preparing it with a mixture of 
solution of galls and iron liquor. 
By the combination of Brazil, logwood, 
archil, and galls, and by browning with 
copperas, a number of different shades are 
dyed : but though their brightness is pleas- 
ing, tliey are not permanent. 
Of dyeing Cotton and Linen dark mixed 
colours. 
Thread and cotton may be dyed a per- 
manent violet, by submitting them, after 
being scoured in the common mode, to a 
mordant prepai'ed by boiling two quarts of 
iron liquor with four quarts of water for 
every pound, carefully removing all the 
scum; and adding to this liquor poured in- 
to a vat, while warm, four ounces of sul- 
phate of copper, and one ounce of nitre to 
the quantity stated. In this tlie skins are 
steeped ten or twelve 'hours, wrung out, 
and dried, and then dyed in a madder bath, 
if suitable to the shade wanted. If a deep 
violet is required, two ounces of verdigris 
must be added to the bath ; and the colour 
becomes still deeper by galling the yarn 
more or less before it is steeped in the 
mordant, if the nitre be omitted. If the 
proportion of nitre is increased, and the 
sulphate of copper diminished, the violet 
inclines more to lilac. By modifying the 
DYN 
mordant in different ways a number of dif- 
ferent shades may be produced. 
To dye cotton different shades of marone 
colour, it is galled, dipped, and worked in 
the usual way in a bath, to which more or 
less iron liquor has been added. It is then 
washed in a bath mixed with verdigris, 
welded, and dyed in a bath of fustic, to 
which a solution of alum and soda are some- 
times added : it is then completely washed, 
after that well maddered, then dipped in a 
weak solution of sulphate of copper, and 
lastly in soap-suds. 
For some hazels and snuff colours, a 
browning is sometimes given by soot, after 
the weldhig, and a madder bath, to which 
galls and fustic have been added ; the soot 
is sometimes mixed with the bath : a brown- 
ing is likewise given by solution of copperas. 
Walm'.t peels also are used for the same 
purpose : the colour they impart is rather 
dull ; but it is not liable to be changed by 
the air into a yellower sliade, as is the case 
in the brownings imparted by means of 
iron. The goodness of this dye, and its 
cheapness, are sufficient to recommend its 
use for grave colours, which are sometimes 
fashionable. 
For calico printing, see Calico Print- 
ing. 
DYNAMICS. This branch of mecha- 
nics relates to the action of forces that give 
motion to solid bodies ; w'hich forces are 
calculated both by their active powers, and 
by the proportion of time in which those 
powers become efficient. Our readers can- 
not fail to perceive, that the complete ana- 
lysis of all appertaining to this subject would 
occupy many formidable volumes; while 
the generality of those who have absolute 
occasion to acquire a complete knowledge of 
dynamics would be led to consult the various 
elaborate publications that have been pub- 
lished, for the edification of such as possess 
that disposition. We must, necessarily, 
study simplicity, so far as our subject may 
admit, and endeavour to bring the most 
prominent matters into a moderate com- 
pass. 
Each body is considered as a mass of 
atoms divisible ad infinitum; the bulk or 
substance of a mass we consider as having 
density ; which relates directly to the quan- 
tity of the matter, and inversely refers to 
the magnitude. We are also compelled to 
consider, that, as the generality of bodies 
are, more or less, porous, their quantity of 
matter is not in every instance found to 
correspond with the bulk they exhibit. 
