Scientific American 11, 16.11.1861
By Professor H. Dussauce.
Painters use very few colors of an organic nature. Those which they employ are usually in the state of lake, which are a combination of the coloring principle, with a metallic oxyd. For some time past I have been occupied with chemical researches on the colorin principles of organic origin, and have obtained one from sandal wood, which, by its beauty and its brightness, is nearly equal to carmine, and is of great interest to painters.
This principle is a pure red solid, melts a little below 212°, and is afterward decomposed. It is insoluble in water and fixed oils, but very soluble in alcohol, ether, acetic acid and volatile oils. Dry chlorine has no action on it; wet chlorine destroys it. All acids - except nitric, chromic and others which are rich in oxygen - have no action on it. Sulphohydric acid, which of all the gases is the most redoubtable test for such colors, has no action upon it; and light and air have no action on it. Painters have found it to be a very solic color. It was used to paint the carriages of the Emperor Napoleon about nine years ago, and the color is still as bright as when it was put on. Its preparation is easy, as follows: - Take the sandal wood in powder, and exhaust it completely by alcohol. In the alcoholic solution thus obtained, pour hydrate of oxyd of lead in excess. Collect the precipitate on a filter. Now, wash the precipitate with alcohol and dry it; dissolve it in acetic acid, and to this acetic solution add an excess of water. The coloring matter which is insoluble in water is precipitated, and the acetate of lead stays in the solution; and it may be used to make new oxyd of lead. Now, wash the precipitate well and dry it at a low temperature. Researchers on this color - too long to relate here - have shown me that this color is a peculiar principle, and is pure santalin. its cost will be about $1 a pound. I intend to make a new compound for dyers and calico printers, extracted from santalin, capable of dissolving in water - a thing which has never been done before.
[Sandal wood, under the name of saunders wood, has been long in moderate use among dyers for dyeing brown colors on woolen goods. It has been considered a variety of bar wood by French chemists. It re-acts with salts aof alumina, and gives red precipitates. We have never heard of it being used for making paints. Barwood and camwood, its congeners, should also produce such paints when heated in the same manner.
- Eds.]
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