100 ANNUAL OF SCIENTIFIC DISCOVERY. 



that, when remelted, some of the cadmium will be volatilizecl, 

 and thus the composition and properties of the alloy will be to 

 a certain extent changed ; by melting, however, at as low a tem- 

 perature as possible, and by adding a small quantity of cadmium, 

 the composition may be kept sutBciently uniform. 



Useful Alloys for Table Use. — Oreide consists of 80 parts of cop- 

 per, 13.0 parts of zinc, and 6.5 parts of nickel. A beautiful while 

 metal, very hard, and taking a fine polish, is composed of 69.8 

 parts of copper, 19.8 nickel, 5.5 of zinc, and 4.7 of cadmium. 



Method of Cutting Glass. — A speedy method is practised in some 

 of the large establishments of France. A jet of highly heated 

 air is directed from a tube on the vase or other object to be cut, 

 which, while made to revolve on its axis, is brought close to the 

 nozzle of the tube. The object being then cooled suddenly, the 

 glass divides at the place operated on with extreme accuracy. 



Extraction of Indigo from Rags. — A French inventor j^laces the 

 rags, cotton or woollen, which have been dyed with indigo, in 

 a boiler provided with a double bottom, and saturates them 

 thoroughly with a solution of caustic soda of l'* Baume. He 

 then keeps them under the action of steam at 45 lbs. pressure 

 for 5 hours. By this treatment the indigo is reduced and dissolved, 

 and may be precipitated from the solution and collected. The 

 indigo thus recovered is said to be as pure as the best commercial. 

 The process will be useful to paper-makers, requiring no more 

 careful sorting of the rags than is usual in paper-mills. 



Bronze Powders. — These colors, according to Dr. Wagner, are 

 really metallic, and not mixtures colored with organic pigments, 

 like carmine and indigo. The metals employed are, for the most 

 part, copper and zinc, an alloy of the two being reduced to an im- 

 palpable powder. The proportions are given as follows, in Ding- 

 ler's ''Polytechnic Journal:" for a bright yellow shade, 83 

 parts of copper, and 17 of zinc ; for an orange shade, 90 to 95 

 of copper, and 5 to 10 of zinc ; for copper red, 97 to 99 of copper, 

 and 1 to 3 of zinc. Tin, silver, and nickel are not used. 



Hair-cutting by Machinery. — M. Nabat has invented a mechan- 

 ical razor, in principle something like a lawn-mower. A helix, 

 with steel blades tangent to a comb, is made to rotate by means 

 of a flexible chain worked by a lever-. One man works the lever, 

 while the operator moves the comb over the body of the animal, 

 regulating the length of hair to be left by the inclination of the 

 comb. It works well on horses and oxen, and may be modified 

 to act on the human head. 



Fire- proof Flooring. — The method found successful in France 

 consists of first spreading upon the planks a layer of clay about ail 

 inch thick, and running uf)on this a layer of asphalte about half 

 an inch thick, — useful in warehouses and granaries. 



Steel Billiard Balls. — Billiard balls are now frequently made of 

 steel instead of ivory ; they are very elastic, and not liable to crack 

 like ivory balls. 



Liquid Glue. — This useful article, for mending porcelain, glass, 

 etc., is best made as follows: 3 parts of glue, in small pieces, 

 should be covered with 8 parts of water, and left to stand lor 



