CHEMICAL SCIENCE. 249 



NEW PLASTIC MATERIAL. 



Five parts of sifted whiting are mixed with a solution of one part of 

 glue. When the whiting is worked up into a paste with the glue, a 

 proportionate quantity of Venetian turpentine is added to it, by which 

 the brittleness of the paste is destroyed. In order to prevent its 

 clinging to the hands whilst the Venetian turpentine is being worked 

 into" the paste, a small quantity of linseed oil is added from time to 

 time. The mass may also be colored by kneading in any color that may 

 be desired. It may be pressed into shapes, and used for the produc- 

 tian of bas-reliefs and other figures, such as animals, &c. It may also 

 be worked by hand into models, during which operation the hands 

 must be rubbed with linseed oil ; the mass must also be kept warm 

 during the process. When it cools and dries, which takes place in a 

 few hours, it becomes as hard as stone, and may then be employed 

 for the multiplication of these forms. Gewerbell. aus Wurtemb., 

 1852. 



INK FOR STEEL PENS. 



Professor Runge has long sought to obtain an ink which would not 

 yield sediment, which should adhere to paper, resist the application of 

 acids, and have no action on steel pens. H has at length obtained a 

 liquid of this kind, containing only Campeachy wood, chromate of 

 potassa, and water. As it contains neither vinegar, gum, sulphates of 

 iron and copper, nor galls, its cost is very moderate. The proportions 

 are 500 litres decoction of Campeachy wood to 500 grammes chromate 

 of potassa. The Campeachy wood is boiled in a sufficient quantity of 

 water to form 80 litres (4^- litres=l English gallon) of decoction from 

 10 kilogrammes of wood (about 20 Ibs). After the liquid is cool, the 

 chromate is added and the whole well stirred. The ink is then ready 

 and may be used at once. Any addition of gum would be injurious. 

 It may appear strange that so little chrome should convert so large a 

 quantity of decoction into ink. But the proportion must not be 

 exceeded, as a larger amount would destroy the coloring matter. If, 

 on the other hand, the proportions here given are observed, a blackish- 

 blue is formed from the yellow pigment of the wood. This is not a 

 suspended precipitate, like the gallate of iron in common ink, but a 

 true solution, from which no sediment can be deposited. A paper 

 written with this ink may be immersed in water for twenty-four hours 

 without injury. Dilute acids do not destroy it or change its tint. The 

 pens used with this ink should be perfectly free from grease, and may 

 for this purpose be cleaned by immersing them in ley of wood ashes. 



MILK FOR MAXUFACTURLXfJ. 



Milk now possesses other offices besides the production of butter 

 and cheese, and the flavoring of tea. It has made its way into the tex- 

 tile factories, and has become a valuable adjunct in the hands of the 



