COMPOSITION OF DURABLE INK. 149 



ganized fubftance, muft be ufed in the inkftand, chiefly for 

 the purpofe of cleaning the pen. 



Red ink may be made by tempering the folution of co P al ?J d ,j"£ t W pf hred 

 with red fulphuret of mercury inftead of lamp black. The mercuri# 

 following proportions of the ingredients produce a red ink 

 which writes very well : 



Take of oil of lavender 120 grs. copal in powder, 17 grs. The recipe. 



red fulphuret of mercury, 60 grs. Diflblve the copal in the oil 



of lavender, and then mix the fulphuret with the folution upon 



a fmooth furface. 



Both thefe compofitions poflefs a permanent colour, and A manufcript 

 i ^ • . . /.,.iri- •,• t>l '-1 written with 



other eflential properties of the ink uled in printing. 1 he oil t h e f e comp ofi- 



of lavender being diflipated with a gentle heat, the colour is tions will not be 

 left on the paper furrounded with copal, a fubftance infoluble j^SSa of * * 

 in water, in fpirits, in acids, or alkaline folutions. A manu- bleaching, 

 fcript, written with thefe compofitions, may therefore be ex- 

 pofed to the procefs commonly ufed for reftoring the colour of 

 printed books, without the fmalleft injury to the writing; and 

 in this manner all interpolations with common ink may be re- 

 moved. 



As 



made and brought into faftiion about thirty years ago, by the cele- 

 brated Wedgwood. Thefe changes appear to be both injurious. 

 For the ink in the cotton is kept blacker by the fufpenfion of the 

 atramentous part ; and if no more ink be prefent than perfectly to 

 fill the cotton, the pen will always receive a fluid black ink, and 

 may be charged at pleafure by a greater or lefs gentle preffure at the 

 time of taking up, or difcharged by lodging the point for a moment 

 upon the cotton. It is alio very eafy to regulate the oxigenation by 

 the air, fo as to increafe the blacknefs without fuffering mouldinefs 

 to come on, by the fimple expedient of turning the cotton upfide 

 down every day. As the fibres of the cotton prevent the fluid from 

 circulating as ufual by the change of temperature produced from 

 evaporation, the interior mafs may be conlidered as in a clofed veffel 

 while not in ufe. 



Mr. More's fountain inkftand, at prefent fo univerfally in ufe, is 

 certainly very inconvenient. The ink, it is true, is kept in a clofed 

 veffel \ but its colouring matter is at full liberty to fublide, and the 

 confumer is obliged to fill his pen from the muddy bottom inftead 

 of the furface j and what is ftill worfe, the conical veflel into which 

 the ink flows, is fubject to all the evils of evaporation and mouldi- 

 nefs, fo as moft frequently to afford an adhefive and clogging fluid 

 to the pen. W. N. 



