Aberration, chromatic, 23;
spherical, 22.
Acetic acid, 66.
Albumen, 63;
preparation of positive paper with, 206.
Alcohol, 70;
used in sensitizing paper, 201.
Ammonia, 71.
Ammonio-nitrate of silver, preparation and use of, 152.
Animal charcoal, 74.
Barium, chloride of, 77.
Baths, glass, 211;
gutta-percha, 34.
Bichloride of mercury for whitening positives, 159.
Bromide and iodide of potassium and silver, 60.
Bromide of potassium, 73.
Bromine, properties of, 72.
Bromo-iodized collodion for positives, (ambrotypes), 58, 59;
for negatives, 60.
Camera boxes, 28.
Camera, construction of, 28.
Camera stands, 31.
Carbonate of soda, 73.
Chemical and visual focus, 21.
China clay, 75.
Chloride of ammonium, 77.
Chloride of barium, 77.
Chloride of gold, preparation of, 83;
for toning, 155
Chloride of sodium, 78.
Chlorine, 75.
Chromatic aberration, 22.
Citric acid, 78.
Cleaning glass plates, 129.
Coating large glasses with collodion, 160.
Collodion, manufacture of, 53;
iodized for positives, 58, 59;
for negatives, 60;
mode of coating glasses with, 131;
vials, 38.
Collodio-Albumen process, Dr. Taupenot, 190.
Color-boxes, 38.
Cutting's patents and correspondence, 173.
Cyanide of potassium, 79;
use of, 63.

Decomposition of light, 16.
Developing solution for positives, 62;
for negatives, 144, 145.
Dippers, glass and gutta-percha, 34.
Double iodide of potassium and silver, 61.
Ether, preparation of, 79.
Fixing positives on glass, 134;
negatives on glass, 146;
positives on paper, 155.
Fluoride of potassium, 81.
Fogging of collodion positives, 137.
Formic acid, 81.
Fulminating gold, 84.
Gelatine, properties of, 82;
for mounting photographs, 157.
Glass, cementing, 158.
Glass plates, cleaning of, 129;
coating with collodion, 131;
coating with albumen, 193.
Glass rods, bending of, 158.
Glycerine, its properties, 82.
Gold, chloride of, preparation of, 85;
for toning, 155.
Grape sugar, 86.
Hadow, Mr., Researches and Formula for making soluble cotton, 46;
on iodizing collodion, 54.
Head rests, 33.
Helio, collodion process for positives and negatives, 164.
Honey, 86.
Humphrey's collodion gilding, 63.
Hydrochloric acid, 87.
Hydriodic acid, 87.
Hydrosulphuric acid, 88.
Hypo bath, 203.
Hyposulphite of gold, 85.
Hyposulphite of silver, 17.
Hyposulphite of soda, preparation and properties of, 89.
Instantaneous positives, 159.
Iodide of ammonium, preparation of, 91;
for iodizing collodion, 58, 59.
Iodide of cadmium, 92.
Iodide of iron, preparation of, 93;
its uses and acceleration, 159.
Iodide of potassium and silver, preparation of, 61;
use in sensitizing collodion, 58, 60.
Iodide of potassium, properties and preparation of, 94.
Iodide of silver, preparation and properties of, 112;
its use in the nitrate bath, 65, 147.
Iodine, preparation and properties of, 90.
Iodized collodion, 58, 59, 60, 131.
Iron, perchloride of, 98.
" protonitrate of, 97.
Jenny Lind stands, 32.
Kaolin, properties of, 75.
Lenses, double-convex, concavo-convex, double-concave, 19.
Lenses, forms of, 19, 20;
combination of, for portraits, 27;
chromatic aberration of, 23;
spherical aberration of, 22.
Leveling stands, 35.
Light, decomposition of, 16.
Litmus, 98.
Manipulations of the positive collodion process, 129;
negative process, 143.
Measures and Weights, 210.
Milk, 99.
Mounting positives on paper, 157.
Negatives for printing positives, 151, 169.
Nitrate of potash, 102.
Nitrate of silver, 116.
Nitrate of silver bath, mode of preparing for positives, 64;
for negatives, 147;
for negatives and positives in Helio's process, 164.
Nitrate of silver used in developing negatives, 145.
Nitric acid, preparation and properties of, 100;
use in nitrate bath, 65, 147;
use in making soluble cotton, 46.
Nitro-sulphuric acid used in preparing soluble cotton, 42, 51.
Oxide of silver, preparation of, 109.
Oxygen, 109.
Oxymel, preparation of, 105.
Paper, sensitive, for printing, 152;
alcohol used in, 201.
Patent for the use of camphor in combination with iodized collodion, 176;
for sealing photographic pictures, 177;
for the use of alcohol as a desiccating agent, 178;
for the use of bromide of potassium in collodion, 178;
for the use of japanned surfaces for taking positives, 179;
for photographic pictures in oil, 181;
for making transparent borders, 183;
coloring positives, 185, 187;
for albumenized collodion, 186.
Plate-Holders, Lewis's patent, solid glass corners for, 137.
Plato vices, 64.
Portrait lenses, combination of, 27.
Positives, (ambrotypes,) process for producing, 129;
by the Helio process, 164;
printing on albumenized paper, 192, 206;
ammonio-nitrate of silver used in, 152;
use of chloride of gold in toning, 155;
fixing, 155;
fixing and brightening, (ambrotypes), Humphrey's collodion gilding
used in, 63;
printing frames for, 36;
collodion for, 58, 59;
mica used for, 136.
Positives, enlarging from negatives, 199.
Potash, 105;
carbonate of, 106.
Practice of the positive collodion process, 129;
negative process. 143;
Helio's positive and negative process, 164;
printing on paper, 151.
Prism, 14;
refraction of light by, 14.
Protosulphite of iron used in developing positives. 62;
negatives, 144.
Pyrogallic acid, preparation of, 107.
Sensitizing paper, use of alcohol in, 201.
Silver, properties of, 107;
removal of stains from the nitrate of, 161;
recovery of from waste solutions, 203.
Solar spectrum, 14.
Soluble cotton, 42;
Hadow on, 46.
Spherical aberration, 22.
Spots upon positives, 139.
Stains and lines upon positives, 139.
Taupenot, M., his Collodio-albumen process, 190.
Test-paper, use of, 205.
Toning bath for positives on paper, 155.
Weights and Measures, 210.

CORRECTIONS.

[Transcriber Note: Corrections have been applied to text.]

On Page 61 and 16th line from the top, for "Iodide of Silver," read Iodide of Potassium.

On Page 167 and 2nd line, for "32 ounces," read 64 ounces.