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The photographic news
- Bandzählung
- 27.1883
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- 1883
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- Hochschule für Grafik und Buchkunst Leipzig
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- Hochschule für Grafik und Buchkunst Leipzig
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Zeitschrift
The photographic news
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Band
Band 27.1883
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- Titelblatt Titelblatt I
- Register Index III
- Ausgabe No. 1270, January 5, 1883 1
- Ausgabe No. 1271, January 12, 1883 17
- Ausgabe No. 1272, January 19, 1883 33
- Ausgabe No. 1273, January 26, 1883 49
- Ausgabe No. 1274, February 2, 1883 65
- Ausgabe No. 1275, February 9, 1883 81
- Ausgabe No. 1276, February 16, 1883 97
- Ausgabe No. 1277, February 23, 1883 113
- Ausgabe No. 1278, March 2, 1883 129
- Ausgabe No. 1279, March 9, 1883 145
- Ausgabe No. 1280, March 16, 1883 161
- Ausgabe No. 1281, March 22, 1883 177
- Ausgabe No. 1282, March 30, 1883 193
- Ausgabe No. 1283, April 6, 1883 209
- Ausgabe No. 1284, April 13, 1883 225
- Ausgabe No. 1285, April 20, 1883 241
- Ausgabe No. 1286, April 27, 1883 257
- Ausgabe No. 1287, May 4, 1883 273
- Ausgabe No. 1288, May 11, 1883 289
- Ausgabe No. 1289, May 18, 1883 305
- Ausgabe No. 1290, May 25, 1883 321
- Ausgabe No. 1291, June 1, 1883 337
- Ausgabe No. 1292, June 8, 1883 353
- Ausgabe No. 1293, June 15, 1883 369
- Ausgabe No. 1294, June 22, 1883 385
- Ausgabe No. 1295, June 29, 1883 401
- Ausgabe No. 1296, July 6, 1883 417
- Ausgabe No. 1297, July 13, 1883 433
- Ausgabe No. 1298, July 20, 1883 449
- Ausgabe No. 1299, July 27, 1883 465
- Ausgabe No. 1300, August 3, 1883 481
- Ausgabe No. 1301, August 10, 1883 497
- Ausgabe No. 1302, August 17, 1883 513
- Ausgabe No. 1303, August 24, 1883 529
- Ausgabe No. 1304, August 31, 1883 545
- Ausgabe No. 1305, September 7, 1883 561
- Ausgabe No. 1306, September 14, 1883 577
- Ausgabe No. 1307, September 21, 1883 593
- Ausgabe No. 1308, September 28, 1883 609
- Ausgabe No. 1309, October 5, 1883 625
- Ausgabe No. 1310, October 12, 1883 641
- Ausgabe No. 1311, October 19, 1883 657
- Ausgabe No. 1312, October 26, 1883 673
- Ausgabe No. 1313, November 2, 1883 689
- Ausgabe No. 1314, November 9, 1883 705
- Ausgabe No. 1315, November 16, 1883 721
- Ausgabe No. 1316, November 23, 1883 737
- Ausgabe No. 1317, November 30, 1883 753
- Ausgabe No. 1318, December 7, 1883 769
- Ausgabe No. 1319, December 14, 1883 785
- Ausgabe No. 1320, December 21, 1883 801
- Ausgabe No. 1321, December 28, 1883 817
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620 THE PHOTOGRAPHIC NEWS. [September 28, 1883. composition is chiefly palmitic and myristic acids, with a little glycerine, but has never been accurately determined. Japan wax, also called “ tree wax,” ought properly to rank as a fat, being a palmitate of glycerine, which latter it yields upon saponification. It is derived from the roots of several trees of genus Shut, chiefly from the Shus succedanea of the East Indies. The use of this wax as an adulterant is checked by its disagreeable odour —otherwise, it is a very useful substance ; it enters largely into the composition of vegetable wax candles, much used us a subsi- tute for those of genuine beeswax. Its sp. gr. is about -999, the m.p. 120° F. There are several other waxes, of great use in their native countries, as palm wax, from the stem of the Ceroxylon andicola, Brazil, and ocuba wax, from the Hyrica ocuba, of the same country; also Andaquies wax, Cuba wax, and others of uncertain animal origin. The two first-named furnish a large portion of the candle power of northern South America. I shall have to defer to next lecture the consideration of vegetable oils and fats, which are also very numerous. For the present, I will conclude with drawing your attention to this unique collection of all kinds of waxes, with a number of different candles with crude wicks, made by island savages as they best knew, for the most part of which I am indebted to the courtesy of Mr. Holmes, of the Pharmaceutical Society’s Museum. Continuing the consideration of those bodies which can be converted into candles without alteration of their chemical nature, we will discuss palm and cocoanut oils : although, like tallow in an unmanufactured condition, their application is very limited. The family of palms is exceedingly large ; and of the number many varieties contribute to the domain of light. I have mentioned the wax palm, which perhaps remits, next to those two which we are now discussing, the largest subsidies to the candle pan ; but all other vegetable sources scarcely furnish a tithe of the quantity which is yielded by the Elais guineenis, the oil palm, and the Elais melanococcus, the cocoanut tree. The former is distributed mainly through the West Coast of Africa, sometimes penetrating pretty far into the interior. Its chief habitat is along the Senegal and Gambia rivers, which are lined with the rude factories where the natives extract the oil. The fruit of this palm weighs about twenty pounds, and much resembles a large artichoke intersected with small golden plums. The dried specimen I exhibit can give you little idea of the beauty of this highly oleaginous fruit as it grows on the tree. The berries are separated from the husks, and by boiling in water, are divested of their unctuous integuments. The deep golden oil floats on the top, is skinned off, and put into casks, where it assumes a granular semi-solid condition. There are many varieties of this oil, of which I have about thirty in these glass bottles, varying from a deep greyish brown to a lemon yellow. The best is that known as • Lagos ” oil. Originally, before the discoveries of Chevreul and Wilson, palm oil, from its soft nature, was of little use, as by pressing it does not become harder; but a certain kind of candle, which was called the “ decimal ” candle, from the fact of ten going to the pound, was manufactured from the “bagged” palmitin, bleached partially by exposure to the air. Messrs. Hempel and Blundell, in 1836, took out a patent for making candles from pressed fats alone. These, however, are little used. Cocoanut candles or candles from pressed cocoanut, were made, but it cannot be said with any success. Whenever candles from the unmanufactured vegetable oils have been introduced, the glycerine present has proved almost as strong an objection in such cases as in tallow. In 1840, Mr. J. P.Wilson took out a patent for making the original “composite” candle, which was a mixture of the pressed cocoanut oil and stearic acid. These were the result of the demand for cheap self-snuffing candles which arose on the occasion of the Queen’s marriage. {Io be continued) 8 Hictionarg of Pkotograghy. ALBUMENIZED PAPER (Printing on).—Continued. Having charged the frame with a negative, paper, and padding, and secured the pressure, place it, glass side uppermost, on the bench out in the daylight. After the lapse of five minutes, the progress of printing should be examined ; until the student is master of the art, he should do this in the printing-room, or he may find the whites of his print very much degraded, more especially the vignettes. Unfasten the spring nearest the head (if it be a portrait) with the right hand, holding the frame, glass side inwards, by means of the left hand; with the right, gently open the released half of the back outwards. Next raise the pad, and print by one corner; the paper, previously white, will now have a picture printed on it, perhaps deep enough, or it may be only just marked, depending upon the density of the negative and the strength of the light; it should be closed up with care, or the paper may not find its way to the position from which it was lifted. Such an effect is observable when we get a double im pression. Turn the frame upside down, release the other spring, now at the top, and examine the other half of the print. If it is progressing satisfactorily, close it up carefully, and again place it out in the light. This operation may be repeated at short intervals until the print is finished. Any portion becoming too dark may be covered with a piece of yellow paper rather smaller than the shadow to be blocked, the most convenient mode of procedure being to gum it on to a piece of glass the same size as the printing-frame, the position of the paper being just over the shadow. The proper time to stop the action of printing can only be determined by individual taste ; but we may say that, as a rule, the printing may be continued until there is slight shading or tone exhibited through all the lights—that is, where the dense parts of the negative have been—excepting the extreme high lights in portraits, such as the most opaque parts of forehead, chin, &c.; we shall then have a print just a trifle deeper than we require when finished ; the reason why we print deeper will be seen when we tone our print. It will be sufficient here to mention, that the prints become lighter in the after operations, depending on the treatment adopted. In the case of dense and under-exposed negatives, sometimes the shadows will be bronzed before the lights are barely touched; this is very noticeable in some early attempts at landscape nega tives. We may be desirous of printing them, although they are not up to the mark ; and exposing the paper to the light before or after printing, either to the front or back, has been found useful by some printers. But if several prints are required, and harmonious results expected, we have recourse to further dodging, and recommend the following ;—Cover the back of the negative with papier mineral or a similar substance, securing it to the edges of the negatives by means of gum; cut the paper away from above the dense portions, so that light is not obstructed. Secure the cut portion to the negative with a touch of gum, and apply sparingly some powdered plumbago to that portion of the paper which covers the deepest shadows. Cloud effects may likewise be produced in v iew pictures by stumping in with plumbago where necessary. Sometimes negatives are exactly opposite to the fore going in printing quality; the lights, not being dense enough, will be printed fully before sufficient strength has been gained i the shadows ; such prints look weak and flat when finished, such a case, a stronger sensitizing bath and more fuming arc bo resorted to. We can also make satisfactory prints by stiPP. over, within the lights on the back of the negative, a little ca ‘
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