imetric Test.=--This is based on the principle that the colour of
a solution of dye-stuff will be proportionate to its strength. Two white
glass tubes equal in diameter are taken. Solutions of the dye-stuff, 0.5
gram in 100 c.c. of water, are prepared, care being taken that the
solution is complete. Of one of these solutions 5 c.c. is taken and
placed in one of the glass tubes, and 5 c.c. of the other solution is
placed in the other glass tube. Of water 25 c.c. is now added to each
tube, and then the colour of the diluted liquids is compared by looking
through them in a good light. That sample which gives the deeper
solution is the stronger in colouring power. By diluting the stronger
solution with water until it is of the same depth of colour as the
weaker, it may be assumed that the depth of the columns of liquid in the
two tubes is in proportion to the relative strength of the two samples.
Thus, if in one tube there are 30 c. of liquid and in the other 25 c.,
then the relative strength is as 30 to 25; and if the first is taken as
the standard at 100, a proportion sum gives

30 : 25 : : 100 : 83.3,

that is, the weaker sample has only 83.3 per cent, of the strength of
the stronger sample.

INDEX.

COMPILED BY MISS GRACE GREENWOOD, B.A. (LOND.)

A.

Acetate liquor, 190, 193.
-- of alumina, 170.
-- of chrome, 180.
-- of lead, 159.

Acetic acid, 174, 180, 184, 227, 231.

Acid dyes;, 83, 159.
-- dye-stuffs, topping with, 228.
-- green, 84, 221, 229, 234.
-- magenta, 84. 220.
-- violet, 229.
-- --6 B, 211, 218.
-- yellow, 220.

Acids, action of, on cellulose, 9.
Acridine orange NO, 231, 232.

Affinity of dye-stuff for fibre, 109.

Albumens, 4.

Algarobilla, 147, 148.

Alizarine, 18, 150, 157, 169, 180, 259.
-- blue, 173, 174.
-- --paste, 174.
-- dyed goods, test of, 258.
-- dyes, 84.
-- oil, 170.
-- orange, 173. 174.
-- pink, 172.
-- purple, 172.
-- red, 171, 248.
-- violet, 172.
-- yellow N, 180.

Alkali blue B, 233.
-- --3 B, 233.
-- --6 B, 217, 232, 233, 238.
-- yellow R, 209.

Alkalies, action of, on cotton, 6.

Alkaline blue, 211, 214, 215, 216.
-- copper solution, 196.

Alpha-naphthol, 130, 132, 133, 186, 187, 188.

Alpha-naphthylamine, 182, 185, 187, 188.
-- claret, 197.

Alum, 159, 164, 165. 166, 167.

Alumina, 157.
-- acetate, 179.
-- mordants, 259.

Amidazol blacks, 79, 121, 179.
-- black G, 124, 126.
-- brown, 121.
-- cachou, 127.
--