MECHANICS AND USEFUL ARTS. 99 



By mixing cold 4 parts of the latter with 1 part of the former, 

 a green liquid is obtained, which can be used immediately for 

 tracing characters upon linen ; the marks are at first green and 

 graduallj' become black. The solutions must be kept separate 

 until required for use ; the mixture may be diluted so as to flow 

 easily from a pen, without diminishing the intensity of the tint. 

 Heat causes the black color to appear immediately ; a steam heat 

 is sufficient, and is better for the fabric than a hot iron. The linen 

 is afterward to be washed in warm water with soap. This ink is 

 not afi"ected by acids or alkalies, and is remarkably permanent. — 

 Chemical News. 



NEW ANILINE DTE. 



Geranosine is prepared by making first a solution of 1 kilo- 

 gramme of any salt of rosaniline in 1,000 litres of boiling water, 

 which is then allowed to cool to 45° C. Another solution is made 

 by first mixing 4^ kilogrammes of binoxide of barium with 35 litres 

 of cold water, and then adding 10 kilogrammes of sulphuric acid. 

 The two solutions are then mixed. The mixture immediately be- 

 comes lemon-yellow in color, but in a short time nearly colorless. 

 The sulphate of baryta is then separated by filtration. The filtered 

 solution is then gradually heated, and, as the boiling-point is 

 reached, assumes a red color, reaching its greatest intensity after 

 2 minutes' boiling, and is then ready for dyeing. The shade of 

 color is that known as ponceau, almost as brilliant as the same 

 shade produced by cochineal. Acid brightens, and ammonia 

 discharges it. It is evidently an oxidized product of rosaniline. 

 When precipitated from its solution, the new compound is soluble 

 in alcohol, and partially so in acids. 



SUMMARY OF IMPROVEMENTS IN THE MECHANIC AND USEFUL 



ARTS. 



Aluminium Bronze. — M. Evrard, in making this bronze, does 

 not combine the copper and aluminium directly, but makes use of 

 a pig iron containing aluminium. This is slowly heated to fusion, 

 when copper is added to the melted mass. Having more aflinity 

 for copper than for iron, the aluminium abandons the latter and 

 combines with the copper. After it has been well stirred it is 

 allowed to cool slowly, so as to jiermit the bronze, which is denser 

 than iron, to find its way to the bottom of the crucible. The same 

 process may be emploj'ed to obtain a bronze of silicium ; indeed 

 the affinity of copper for silicium is energetic enough to induce 

 M. Evrard to try this method for separating silicium from pig iron 

 by adding a proper quantity of copper. — American Artisan. 



Very Hard Alloy. — By melting together 500 parts of lead, 300 

 parts of tin, and 225 parts of cadmium, a very hard alloy may be 

 made, fit for stereotype plates and for backing up electrotypes. 

 It is said to be harder and better for the above purposes than thtit 

 made with bismuth, and it is also cheaper. An objection to it is 



