514 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



becoming like a resin, and balling together into greenish 

 bumps of a metallic lustre, in which condition the liquid is 

 entirely unfit for dyeing. 29 C, February, 1872, 51. 



ACTION OF SALINE WATERS IN DYEING. 



It has generally been assumed that water containing saline 

 matters is unsuited for dyeing and bleaching ; but a corre- 

 spondent of Reimann's Fdrber-Zeitung writes to say that the 

 water of his village, which contains a little salt and some 

 lime, is so far from being injurious to the process that it fur- 

 thers it in a decided degree. In cotton dyeing an inequality 

 of color in the yarn is often met with ; but the correspondent 

 in question maintains that this is never the case in his neigh- 

 borhood. In boiling out the cotton, whether in the yarn or 

 in the piece, it comes out from the kettle already half white, 

 thus far lighter than when boiled in ordinary non-saline wa- 

 ter. The theory of this process is found in the suggestion 

 that saline water boils at a higher temperature than pure 

 water. Aniline colors, when used with saline waters, accord- 

 ing to his experience, are more beautiful, and light blue is 

 never as fine as when saline water is employed. Should this 

 communication prove to be founded in fact, it would be a 

 question as to what extent common salt is to be hereafter 

 added to the water for dyeing purposes. 24 (7, 1872, ix., 66. 



SUBSTITUTE FOR LITHOGRAPHIC STONE. 



A substitute for lithographic stone has been introduced. 

 For the purpose in question, the inventor takes a block or 

 slab of slate, or other material, which is to be made perfectly 

 smooth and true, and then coated with glue or other gelatin- 

 ous matter. In some instances he adds a solution of silicate 

 of soda and bichromate of potash, or uses this solution alone. 

 The coated block is exposed to the sunlight, and then washed 

 to remove the superfluous coating, and, after being dried, it 

 is ready for drawing or writing upon. The ink, or pigment, 

 is prepared w T ith albumen, or other gelatinous matter, dis- 

 solved in a saturated solution of bichromate of potash, either 

 with or without chrome alum, and with a small quantity of 

 ivory-black to render the ink visible. The picture is drawn 

 upon the prepared block with this ink, and exposed to sun- 

 light, and afterwards the surface is covered with gum or glyc- 



