M. TECHNOLOGY. 525 



(uncalcined), and one part of borax, which are finely pow- 

 dered, thoroughly mixed together, and fused in a crucible, 

 and, when cold, again reduced to fine powder. A paste, made 

 by mixing this with water, is spread upon the copper with 

 a brush, and dried with gentle heat, after which sufficient 

 heat is to be applied to bring the compound into fusion, 

 when a white and firmly adhering enamel will, it is said, re- 

 sult from the operation. 13 (7, ix., 1872, 616. 



INDESTRUCTIBLE WRITING-INK. 



The following receipt is given as furnishing an indestructi- 

 ble writing-ink. One drachm of aniline black is dissolved in 

 three quarters of an ounce of alcohol, to which sixty drops 

 of concentrated muriatic acid are to be added. This solu- 

 tion is of a deep blue color, and is to be diluted with three 

 ounces of water in which three quarters of an ounce of gum 

 arabic has been dissolved. It is asserted that such ink does 

 not corrode steel pens, and can not be destroyed, either by 

 acids or by alkalies. 9 (7, 1872, 73. 



LINOLEUM, A NEW FABRIC. 



A new fabric, by the name of linoleum, has lately been in- 

 troduced in England, where it has met with great favor. It 

 consists essentially of water-proof sail-cloth upon which a 

 mixture of pulverized cork-wood and oxidized linseed oil is 

 thoroughly fastened by rollers. It is made quite ornamental 

 by tasteful prints in lively colors, and is used for carpeting 

 stairs and corridors, for rugs before sofas and tables, for all 

 kinds of matting, etc. It is considered quite valuable on ac- 

 count of its softness, durability, and indifference to moisture, 

 Jieat, or cold, and is said to deaden the sound of footsteps or 

 other noise more completely than kamptulicon. 18 (7,xx.,317. 



FIRE-PROOFING WOOD. 



According to Sieburger, the following application will 

 render wood measurably fire-proof. The surface to be pro- 

 tected is to be painted twice with a hot solution of three 

 parts of alum and one part of copperas. When perfectly 

 dry, a third coat is given with a diluted solution of copperas, 

 to which just enough white fuller's earth is added to bring it 

 to the consistency of a good paint. The alum and copperas 



