INKS. SQ5 



Printer's INK. This is a very singular composition, partaking 

 much of the nature of an oil varnish, but differing from it in the 

 quality of adhering firmly to moistened paper, and in being to a 

 considerable degree soluble in soap.water. 



It is, when used by the printers, of the consistence of rather thin 

 jelly, so that it may be smeared over the types readily and thinly, 

 when applied by leather cushions, and it dries very speedily on the 

 paper without running through to the other side, or passing the 

 limits of the letter. 



The method of making printer's ink is thus described by Dr. 

 Lewis. Ten or twelve gallons of nut-oil are set over the fire in a 

 large iron pot, and brought to boil. It is then stirred with an iron 

 ladle, and whilst boiling, the inflammable vapour rising from it 

 either takes fire of itself, or is kindled, and su fie red to burn in this 

 way for about half an hour, the pot being partially covered, so as 

 to regulate the body of the flame, and consequently the heat com. 

 municated to the oil. It is frequently stirred during this time, that 

 the whole may be heated equally, otherwise a part would be 

 charred and the rest left imperfect. The flame is then extinguished 

 by entirely covering the pot. The oil by this process has much of 

 its unctuous quality destroyed, and when cold is of the consistence 

 of soft turpentine, and is then called varnish. After this it is 

 made into ink by mixture with the requisite quantity of lamp-black, 

 of which about two ounces and a half are sufficient for sixteen 

 ounces of the prepared oil. The oil loses by the boiling about an 

 eighth of its weight, and emits very offensive fumes. Several other 

 additions are made to the oil during the boiling, such as crusts of 

 bread, onions, and sometimes turpentine. These are kept secret 

 by the preparers. The intention of them is more effectually to 

 destroy part of the unctuous quality of oil, to give it more body- 

 to enable it to adhere better to the wetted paper, and to spread on 

 the types neatly and uniformly. 



Besides these additions, others are made by the printers, of 

 which the most important is generally understood to be a little fine 

 indigo in powder, to improve the beauty of the colour. 



Red printer's ink, is made by adding to the varnish, about half 

 its weight of vermilion. A little carmine also improres the colour. 



INK, Sympathetic^ a liquor employed for writing on paper, so 

 that it may retain its natural whiteness after the letters are formed, 



