M. TECHNOLOGY. 545 



M. TECHNOLOGY. 



IMPROVED TEACING-PAPEE. 



Puscher, of Nuremburg, has lately suggested a solution of 

 castor-oil in absolute alcohol for the purpose of manufacturing 

 a tracing-paper. The oil is to be diluted with one, two, or 

 three times its bulk of alcohol, according to the thickness of 

 the paper, and the amount consequently required for rendering 

 it transparent. This can be laid on by means of a sponge ; 

 and in a very few minutes after the application the paper will 

 be dry, transj^arent, and ready for use. It will readily receive 

 the mark of a pencil or India ink, and as by immersion in ab- 

 solute alcohol the oil can be removed, the paper can be restored 

 to its original condition, if desired. 13 6', Oct. 15, 1872, 1363. 



INERASIBLE STAMPIXG-INK FOR LINEX, ETC. 



Professor Bottger gives the following formula of an ink for 

 marking linen, etc., that he maintains to be entirely unaffect- 

 ed by chloride of lime, cyanide of potassium, caustic potash, 

 or acids. Digest coarsely powdered cashew nuts, for some 

 time, at a moderate temperature, in a closed flask, with petro- 

 leum naphtha ; then allow the exceedingly volatile solvent to 

 evaporate. . After marking articles with the resulting sirupy 

 liquid, moisten the place with aqua ammonia or lime-water, 

 and the marks will instantly assume a deep, permanent black 

 color. 13 C, December 15, 18'72, 1627. 



RED INDELIBLE INK. 



According to Dr. Eisner, an indelible liquid preparation for 

 marking clothing in red characters may be obtained by tak- 

 ing equal parts of green vitriol and cinnabar, finely powdered, 

 sifting them, and rubbing them up very carefully with good 

 linseed-oil. They are then to be passed through a strainer, 

 and the thick fluid which is left is used for writing, with a 

 quill pen. The preparation may be used both for writing 

 and stamping on cotton fabrics. These may afterward be 

 subjected to the operation of bleaching, it is said, without in 

 the least afiecting the ink. 6 C, December 19,1872,508. 



