Fluid Hydrastis is an alcoholic extract of Hydrastis canadensis misciable with water, syrup, and glycerine.

Lacto-pepsin is recommended as a universal remedy for dyspepsia and other diseases of the stomach. It consists of; Milk sugar 40 ounces, pepsin 8 ounces, pancreatine 6 ounces, vegetable ptyalin (diastase) 4 drachins, lactic acid 5 drachins, and hydrochloric acid 5 drachmns.

Thermaline is a mixture of cinchona alkaloids and extract of eucalyptus, and is claimed to be much superior to all other fever remedies, quinine included.

Opodeldoc. Soap free from stearine 12 parts, camphor 8, spirits of wine 320, oil of thyme 1, oil of rosemary 2, and spirit of ammonia 16.

Pepsin Wine with Malt. Prof. Ernst Schmidt, of Lille, France, furnishes the following receipt: Pepsin extract and maltine extract each 5 parts, chloride of sodium 5, good cognac 45, old Chablis wine 400, vin de Grenache de Gollivure 500. By pepsin extract the author means a solution of pepsin prepared in conformity with the directions given in the "Pharmacopoeia," and evaporated to the consistency of thick extract, and to which 10 per cent. of glycerine has been added. The maltine extract is prepared by pouring over crushed malt 10 times its weight of cold water, macerating it for 24 hours, and straining and pressing. Strong alcohol is added to the fluid, causing a copious precipitate to be formed, from which the fluid is after 24 hours filtered off, and fresh alcohol added to it. This is again allowed to settle for 24 hours, when the fluid is carefully poured off, the result being a shiny precipitate and a clear liquid. The latter is distilled to regain the alcohol, while the precipitate is evaporated to the consistency of a thick extract, and then compounded with 10 per cent. of glycerine.

Plastic Bandage. Tissues or textures of any material are saturated

Preparation of Sticking Plaster. Boil in a copper pan 175 parts of pulverized litharge and 300 parts of olive oil, adding occasionally a few drops of water, to the consistency of plaster, which is stirred at a gentle heat until all the water has been evaporated and the mass has a grayish-white color. Remove it from the fire, and, while yet warm, add a mixture of 200 parts of rosin and 400 parts of common turpentine. Then evaporate, with constant stirring, until it ceases to foam, cool it and break into pieces or mould into sticks.

New Sticking Plaster by Dr. A. Hew son. Dissolve glue in boiling water. Compound the solution with 25 per cent. of officinal acetic acid, perfume with rose oil, and spread it upon paper, gauze or muslin.

Galbanum and Saffron Plaster. Place in a copper pan 200 parts of simple lead plaster and 66 parts of yellow wax. Let the compound cool off somewhat and then add 200 parts of purified galbanum, previously dissolved on the water-bath, in 33 parts of ordinary turpentine, and finally 20 parts of pulverized saffron, and mix the whole thoroughly.

Saffron Plaster. Melt together in a copper pan 250 parts each of yellow wax and rosin, and strain through a

treated with collodion. Ether and chloroform compounded with the above acid mixture also dissolves gelatine.

Soup Plaster. Melt in a porcelain dish 150 parts of simple lead plaster and 25 parts of yellow wax and mix the compound with 10 parts of pulverized Castile soap.

Powdered Camphor. Glycerine is the simplest and most efficient substance to keep camphor in a finely divided state. Mix 2 parts of glycerine in 10 parts of alcohol and triturate it with 150 parts of camphor to a fine powder.

Antarthritic Papers. Buchner's Antarthritic Paper. Digest 11 parts of pulverized euphorbium, 22 parts of cantharides powder in 234 parts of 90 per cent. alcohol. When thoroughly extracted, compound the extract with 11 parts of Venetian turpentine, then immerse fine paper in the mixture, and dry it in the air.

English Antarthritic Paper. Digest 29 parts of pulverized euphorbium and 14.5 parts of pulverized cantharides in 146 parts of alcohol for 8 to 10 days; then filter, and dissolve in the filtrate 58.5 parts of white rosin and 44 parts of Venetian turpentine. Apply three coats of the resulting varnish-like solution to thick letter-paper.

PHOTOGRAPHY.

Alcoholic Solution of Gelatine is easily prepared by allowing the hard gelatine to swell up in water, then melting and finally adding 4 to 5 times its quantity of 95 per cent. alcohol. The solution remains entirely clear, runs off like collodion, and dries far quicker than gelatine emulsion with 5 per cent. of alcohol, and it can be compounded with ammonia to basic reaction without injuring its firmness.

According to Herschel, a mixture of 1 part of dilute nitro-muriatic acid and 48 parts of rectified spirit of wine dissolves almost any quantity of heated gelatine. Poured over plates the solu

Alkaline Gelatine Developer. Dissolve 1 ounces of Nelson's amber gelatine in 2 fluid ounces of water over a water-bath, then add 1 fluid ounce of saturated solution of caustic soda, and boil until the solution is thinly fluid. Take 1 part of this solution to 8 parts of solution of pyrogallic acid in the proportion of 1 to 250. No bromide of potassium is required; expose for a very short time; an overexposure cannot be remedied.

Chloride of Silver and Gelatine Emulsion. Water 1000 parts, gelatine 50, nitrate of silver 15, chloride of lime 5, citric acid 5 to 10. Dissolve each chemical by itself in a part of the water. Then add to the gelatine first the nitrate of silver, next the chloride of lime, and finally the citric acid. It does not matter should the emulsion become red. It is now ready for use without washing. Coat glass plates with the emulsion and print quite dark in the photo-printing frame. shades bronze quickly and the intensity with workable emulsion is good. In case the tones are a dirty yellow instead of black the quantity of citric acid must be increased, which will always rectify this evil. The diapositives thus produced must be still further toned, which is best done in a bath of cyanide of gold. It is fixed with weak hyposulphite, then washed, tanned with alum, and finally washed again.

The

Claudet's Instantaneous Positive Paper. Float the paper on a solution of 500 parts of distilled water and 20 parts of corrosive sublimate, then dry it and wash with a solution of 5 parts of nitrate of silver in 60 parts of distilled water. The negative is exposed to the light over this prepared paper for 2 seconds to 1 minute. The picture is developed by immersion in a bath of 1 part of sulphate of iron, 1 parts of radical vinegar, and 30 parts of distilled water. The positive picture is then washed and fixed with sodium hyposulphite.

Cleansing Mixture for Glass Plates. Mix two parts of alcohol, 1 of ammonia, and 15 of water.

Cleansing Fluid for Glass Plates. This is especially efficient in case iron salts have been used for the developing bath. Mix 30 parts of water, 7 parts of hydrochloric acid, and a trace of iodine. Rub the plate with a linen rag moistened with the fluid, and then polish in the usual manner.

Clear Caoutchouc Solutions. Tie 30 parts of caoutchouc, cut up in small pieces, in a small linen bag, fasten this to the cork of a bottle containing 1000 parts of benzine, in such manner that it floats upon the surface of the benzine. Allow it to stand perfectly quiet for 6 to 8 days. During this time the soluble portion of the caoutchouc passes over into the benzine, while the contents of the bag swell up enormously. The resulting solution, which is as clear as water and thickly fluid, contains 1.2 to 1.5 per cent. of caoutchouc. The swelled residue retains about to

of the benzine used, and may serve for the manufacture of an ordinary caoutchouc varnish.

We would here remark that a solution of caoutchouc in benzine kept in halffull bottles becomes decomposed when exposed to light; that is to say, a thickish solution becomes thinly fluid and is no longer available for photographic purposes. Although the solution will undergo the same change when kept in the dark it requires at least three times as long.

Damson's Tannin Plates. 1. Receipt for the Collodion Cotton. Sulphuric acid of 1.840 specific gravity 1000 parts, nitric acid of 1.450 specific gravity 360 parts, water 240 parts, and cotton 50 parts.

the plate is then washed and dipped into the mixture.

Davanne's Intensifier. In case a plate has been spoiled it is, after exposure, only partly developed and fixed with solation of cyanide of potassium. The plate, after having been freed from the last traces of the fixing salt by washing, is treated twice or several times with a solution of 2 grains of pyrogallic acid, 1 grain of citric acid, and 10 drops of radical vinegar in 1 fluid ounce of distilled water, to which a few drops of a solution of silver of 15 per cent. have been added. It is next treated with the following fluids:

1. Iodine 5 grains, iodide of potassium 10 grains, and distilled water 1 fluid ounce.

2. Sulphate of potassium 1 drachm, distilled water 6 fluid ounces.

Solution No. 1 is poured over the plate either in daylight or in the dark room, and allowed to remain upon it until the precipitate is perfectly yellow; it is then rinsed off with water and solution No. 2 poured upon it, and this allowed to remain until the yellow color is changed into a deep brown.

Developing Solution of Oxalate of Iron. The following receipt is by H. W. Vogel: a. Neutral oxalate of potassium 9 ounces, water 1 quart. b. Sulphate of iron 31 ounces, water 103 fluid ounces, sulphuric acid 2 to 3 drops. A supply of both solutions should be kept on hand. For use mix 3 volumes of a with 1 of b. Should the plates appear clouded add to 4 fluid ounces of the mixed solutions several drops of a solution of bromide of potassium, containing 3 parts of bromide to 50 of water.

3. Solution of Tannin. One part of taunin dissolved in 30 parts of distilled

water.

Developer for Gelatine Plates. Mottu, of Amsterdam, uses the following formula for developing emulsion negatives: Saturated solution of potassium ferricyanide and water each 120 parts, and pyrogallic acid 1 part. Before using the developer a few drops of ammonia are added to every 15 parts of it;

the number of times of enlargement required and add the focal length to the product. For instance, the negative is to be enlarged 3 times with an objective having a focal length of 4 inches; the ground glass of the camera must be 16 inches from the lens, viz.: 3X4+4 inches of focal length equals 18 inches. The distance the negative is to be in front of the lens is always more than the focal length, but less than twice the focal length.

Email Photographs. The object of this process is to treat photographic pictures in such a manner that they appear to stand out from the surface of the picture. The process is as follows: The photograph is carefully colored with fine gum colors, mostly transparent. The negative is covered on the collodion side with a good glass plate free from scratches, and fastened to it with clamps. The outlines of the figures are then drawn upon the glass plate with a fine brush, and black spirit lacquer and the ground of the negative filled in with the same kind of lacquer, so that only the figures remain free and clear. The glass plate is now removed from the negative, and the coating with spirit lacquer, after the first coat is dry, is repeated. The coating is now allowed to dry thorough ly; the black negative mask is then placed exactly upon the colored positive, and both joined together on the edges with strips of paper. Although the colored figure lies in reality behind the black glass plate, it seems nevertheless to stand out from it.

Gelatine Emulsions. Abney confirms the observations of others that gelatine emulsions become more sensitive with age. He states also that emulsion plates inclined to curl lose this fault entirely after having been kept for some time. He also recommends the following process for intensifying weak plates: The plate, after having been fixed, is first washed for half an hour with fresh water, which is changed every 10 minutes, then placed for half an hour longer in a mixture of 1 part of diluted dioxide of hydrogen and 60 parts of water, and finally washed with pure water for 5 minutes. The intensifying solution consists of: I. Pyrogallic acid and citric acid each 1 part, and water 480 parts. II. Nitrate of silver 1 part, water 24 parts. To 30 parts of No. I add 1 of No. II. The intensifying must be done in the dark room.

Glacé or Enamelled Photographs. Over a perfectly clean glass sprinkle pulverized tale and with a tuft of cotton rub it on the glass with a circular movement until every particle of the tale disappears. The tale gives a surface to the glass that assists in lifting

the enamelled print from it. Now flow the plate with collodion prepared as follows: Four and one-half fluid ounces of ether, 3 fluid ounces of alcohol, sufficient cotton to thicken, and 24 drops of castor oil. When this flow is dry, apply the prints face downward, after immersing them in a solution of gelatine made as follows: Cox's gelatine 1 ounce, water 8 fluid ounces, and glycerine 50 drops. Add the gelatine and glycerine to the water, and let it stand over night, when it will be ready for use after filtering. Allow the prints to remain in this solution about 5 minutes before laying them on the collodionized glass, and then pass a gum roller lightly over them to press them tightly to the glass, and also to remove the excess of gelatine. After the prints are nearly dry they are ready for the mounts. For this purpose light Bristol board is best. Use the gelatine solution for mounting and mount on the glass as the prints lie. It is a good plan to lay upon the back, after the mounts have been applied, a weight of some kind, as a heavy piece of glass, which should remain there for an hour at least. This assists in securing a complete contact to the print. The whole must be perfectly dry before an attempt is made to remove the prints from the glass. When they are thoroughly dry run a knife blade around the edge to start them up; and if the work has been properly done they will come off all right. Careful manipulation is the only surety for success. A little experience will enable any one to perform this operation well.

Gold and Fixing Baths. As soon as the impressions come from the printing frame they are drawn through 3 or 4 washing waters, and then immersed in a dish with water to which a handful of common salt has been added.

Toning Bath. Chloride of gold 1 grain, sodium acetate 32 grains, sodium carbonate 4 grains, water 8 fluid ounces. The following solution should be kept on hand: Chloride of gold 15 grains, sodium acetate 1 ounce, water 123 fluid ounces, some of this being added from time to time to the toning bath as it becomes weaker by use. The copies, after toning, are several times washed with water containing some common

The fixing bath is previously neutralized with sodium carbonate or ammonia.

New Intensifying Buth for Gelatine Negatives. Mix successively the following solution: a, corrosive sublimate 4 parts, and water 200; b, iodide of potassium 6 parts, and water 66; and c, sodium acetate 8 parts, and water 66. This intensifying bath has the advantage over other solutions that it can be used immediately after fixing the plates, and it gives the requisite intensity, even to the thinnest negatives, in a few minutes.

New Developer for Bromide of Silver Dry Plates. Edwards' glycerine pyrogallic developer is superseding the simple pyrogallic developer, having greater scope in the exposure and control of the development. The following solutions are used: A. Pyrogallic acid and glycerine each 1 part, and alcohol 6. B. Bromide of potassium 1 part, ammonia of 0.880 specific gravity and glycerine each 8, and water 50. Both concentrated solutions keep for a long time. For use in developing pour 30 parts of water into a saucer, add 1 part of solution A, and a like quantity of solution B, and submerge the emulsion plate in it. With a correct exposure the image appears in a few seconds, and the development is finished in a minute. Should the picture, in consequence of over-exposure, appear too suddenly, the developer must immediately be poured off, water poured into the saucer and some of solution A added, which with the residue of the remaining ammonia will sufficiently develop the plate.

New Method of Preparing Emulsion, especially in hot weather and which saves all washing, is as follows: Prepare the following solutions: I. Silver 400 parts, water 2800 parts. II. Bromide of ammonium 240 parts, gelatine 24 parts, water 2800 parts, and acidulate slightly with hydrochloric acid. III. Gelatine 20 parts, water 465 parts. IV. Hard gelatine and soft gelatine each 240 parts, water 2230 parts. When No. II. is melted add gradually No. I. and boil for hour. Then cool it to

I.

New Photo-printing Receipts. Preliminary Preparation. Flow thoroughly cleansed plates with the following mixture: Potash water-glass 1 part and Pilsen beer 11 parts. When all the plates have been flowed heat them somewhat and let them stand till the next morning, when they are again heated, washed, and stood aside to dry.

II. Chrome-gelatine Layer. Wash 25 parts of gelatine in several waters and let them swell up in the last water. Then dissolve 7.5 parts of chrome-alum in 200 parts of distilled water, add the soaked gelatine, and heat the whole to 120° F. When the gelatine is entirely dissolved add 2.5 parts each of bichro mate of potassium and bichromate of ammonium. The plate before flowing is somewhat heated.

Fixing Solution. Glycerine 500 parts, ammonia 50, hyposulphite of sodium 12, and water 250.

Fluid for Drawing off Negatives. Gelatine 36 parts, radical vinegar 100, and glycerine 6 to 8. The solution remains liquid even on cooling, and the negatives can be flowed cold.

Painting the Operating Room. Blue, which is generally used, prolongs the taking of a picture instead of accelerating it. The best paint for the walls of the operating room is an orange-green, obtained by mixing orange with peagreen. If, further, the collodion layer and the silver-bath are colored violetthe complementary color of orangegreen-the picture is under favorable conditions taken instantaneously, while under less favorable circumstances it requires but 2 to 3 seconds.