After toning, wash well and dry: they dry quickly. Varnish with Soeh-nee crystal varnish, then mount with covering glasses, and mark. Bind round the edges with paper and very stiff gum, and the picture is complete.

The making of a really good transparency is by no means an easy or pleasant task with a wet collodion plate, but with these dry plates an amateur can, with a little practice, produce comfortably, slides quite equal to those procurable from professional makers. (T. N. Armstrong.)

Ground

Mix the whites of 2 eggs, well beaten, 6 pints water, and 1 dr. liquid ammonia.

Collodion Formula

Mix 6 oz. sulphuric acid, 4 oz. nitric acid at 1.450 sp. gr., and 2 oz. water. The temperature will rise to about 170° F. (77° C); when it has cooled down to about 100° F. (38°C), immerse perfectly dry cottonwool (best carded and of long fibre), pull it in under the acid with a piece of glass rod, and let each piece be well saturated before adding another. Cover the vessel, and leave it for 12-20 hours in a situation where any fumes generated may escape into the outer air. Next lift the cotton out, and plunge it quickly into a large quantity of water, separating the tufts with pieces of glass; wash in changes of water till no acid is left. Wring the cotton in a coarse towel as dry as possible, and then pull out the tufts, and place them in the air to dry. Collodion made with this cotton will be very soluble and leave no sediment; 5-6 gr. will dissolve in 1 oz. mixed ether and alcohol, and still the collodion will be very fluid.

To prepare one pint of collodion with above: -

(a) Alcohol ...... 10 oz.

Sulphuric ether .. .. 5 oz. Cotton as above .. .. 100 gr.

To Iodise: -

(6) Alcohol ...... 5 oz.

Ammonium iodide .. 60 gr.

Cadmium iodide .. .. 30 gr.

Cadmium bromide .. 20 gr.

Shake till dissolved, and then pour into («).

Another plan, better for small quantities : -

Dissolve the iodides, as above, in 10 oz. alcohol, then put in 100 gr. cotton, and shake well. Lastly, add 10 oz. ether, and shake till cotton is dissolved. This collodion will be ready for use in a few hours, but will improve with age.

Saturated Iron Solution

Fill a Winchester quart } full of crystals of iron protosulphate, and add 1 oz. copper or zinc sulphate. Fill up with water, shake well repeatedly. Carefully cork the bottle, and lay it gently on its side until next morning. Again shake, and the solution will be ready for use. Always keep fall up to stopper with water. Always have the bottle half full of crystals. The use of the copper or zinc sulphate is to prevent the formation of sediment of iron persulphate.

Developer with above Solution.

Iron protosulphate (sat. sol. as above) .. .. 2 fl. oz.

Acetic acid ...... 1 oz.

Water........ 20 oz.

Iron Developer for Negatives, Iron protosulphate (sat. sol.)........ 2 fl. oz.

Copper sulphate .. .. 1 dr. Baryta nitrate .. .. 1 oz. Glacial acetic acid .. 1/2 oz.

Water........ 20 oz.

When dissolved, filter out white deposit, and keep closely corked.

Henderson's Iron Developer.

Iron protosulphate .. .. 20 gr.

Glacial acetic acid .. .. 20 m.

Alum ........ 40 gr.

Water ......• .. 1 oz.

Nitrate of Iron Developer for Ferro-types.

Iron protosulphate .. .. 1 1/2 oz.

Baryta nitrate...... 1 1/2 oz.

Nitric acid ...... 20 drops

Water ........ 20 oz.

When dissolved, filter from dense white deposit of baryta sulphate, and keep in closely corked bottle. N.B. - It rapidly spoils when exposed to the air. Pictures by this process are of a very brilliant pearly white.

Collodio-chloride Printing Process.

16-gr. alcoholic solution of silver nitrate, 1 oz. (by pounding silver salt with methylated spirit in a mortar).

Sulphuric ether...... 1 oz.

Pyroxyline...... 12-14 gr.

When dissolved, add 1 1/2 dr. 16-gr. alcoholic sol. calcium chloride; shake well, and keep carefully from light. A sizing of arrowroot should be applied to paper before pouring on collodio-chloride.

Intensifying Solution for Wet-plate Negatives.

(a) Iron protosulphate (sat. sol.)........ 2 oz.

Acetic acid .. .. .. 1 oz.

Citric acid .. .. .. 1/2 oz.

Water........ 20 oz.

Silver solution, as much as is necessary to make negative dense.

(6) Pyrogallic acid .. .. 10 gr.

Citric acid...... 25 gr.

Distilled water .. .. 2 oz.

Add a few drops of silver nitrate solution, 10 gr. per oz.

Developer for very delicate Transparencies.

Pyrogallic acid...... 3 gr.

Citric acid.. .. .. .. 1 gr.

Water.......... 1 oz.

This development is slow, but the deposit is very fine. Tone with gold, 1 gr. to 10 oz. water.

Durable Sensitised Paper.

Float the albumenised paper on a 10 per cent. solution of silver nitrate for 4 minutes, draw it over the glass rod to drain, and then float the back of the sheet for a like period upon a bath composed of

Potash oitrate.. .. .. 1 part

Water ........ 30 parts

Final wash in rain water. Gold sulpho-cyanide toning suits best with this formula.

Werge's Gold Toning Bath.

(a) Borax........ 1 oz. dissolved in hot water; when all dissolved, dilute to 80 oz. Keep this in Winchester quart as stock solution. To tone, take for each gr. of gold 8 oz. of above solution; mix. The bath is ready for work at once.

(6) Gold chloride .. .. 1 gr.

Soda acetate...... 20 gr.

Water........ 8 oz.

(a) Gold chloride .. .. 1 gr. Whiting ...... 30 gr.

Pour on 8 oz. boiling water, and stir. Now add 1 drop saturated lime chloride solution. When, cool, bath is ready for use.

(6) Gold chloride .. .. 1 gr. Soda bicarbonate .. 3 gr. Water........ 8 oz.

To be used at once.

(c) Gold chloride .. .. 1 gr. Soda phosphate .. .. 30 gr. Water........ 8 oz.

Collodion Enlargements - Croughton's Method.

Soak polished flatted crown glass in soda for some time. After well washing, immerse in weak sulphuric or hydrochloric acid, say 1 oz. to 1 qt. of water, Rinse well, and dry with clean cloth Polish with wash-leather. Well was polished side of glass with waxing solution made as follows: -

Yellow beeswax...... 1 dr.

Benzole ........ 3 oz.

Use weak acid bath of silver nitrate. Develop with iron as follows: -

Iron protosulphate .. .. 6 dr. Glacial acetic acid .. .. 2 oz.

Citric acid...... 60-80 gr.

Sugar-candy ......30 gr.

Water..........20 oz.

Fix in hyposulphite 4 oz. to 1 pint water. Well wash. For transfer, use Autotype double transfer paper. Soak 20 minutes in cold water. Now place paper in hot water till surface feels slimy. Place face down on the wet collodion surface, and gently squeegee. When dry, the picture will come from glass.

Printing on Fabric.

Remove all dressing from fabric by boiling in water containing a little potash, dry, and albumenise with 2 dr. ammonium chloride, 62 dr. water, and the white of 2 eggs, all being well beaten together. A 70-gr. silver bath is used, and the remaining operations are as for paper.

Winter's Canvas Enlargements. Salting solution: -

Potassium bromide .. 3 parts

Potassium iodide .. .. 1 part

Cadmium bromide .. 1 part

Water........ 240 parts

German canvas is said to be better than English. This is immersed in the above, and when saturated, is drawn over glass rod and hung up to dry; it is then placed in a sensitising bath made as follows: -

Silver nitrate .. .. 4 parts

Citric acid...... 1 part

Water........140 parts drawn over rod as before; when dry, is ready for exposure, which should be continued until outline of image is visible.

Developer.

Pyrogallic acid .. .. 10 parts

Citric acid...... 45 „

Water........ 410 „

This should be used at a temperature of 86°-104° F. (30°-40o C), the canvas again immersed, and rocked to and fro until sufficiently out; washed freely, and fixed in the usual hypo solution; canvas being more permeable than paper, less after-washing is necessary.