428 PROFESSOR TRAILL ON THE COMPOSITION OF A NEW WRITING-INK. 



3. Its colour, compared to common ink, is at once full ; and it is not liable 

 to change by time. 



4. It is not affected by soaking or washing with water, as long as the texture 

 of the paper is unchanged. 



5. Slips of paper written with my ink, immersed for twenty-four hours in a 

 solution of chlorine, capable in a few minutes of effacing common ink, underwent 

 no change ; and even when immersed for seventy-two hours, the ink was not im- 

 paired in colour or adhesion. 



6. Similar experiments were made with a mixture of chloride of lime and 

 water, acidulated with sulphuric acid ; 



7. With diluted nitro-muriatic acid ; 



8. With a saturated solution of oxalic acid ; 



9. With diluted sulphuric acid ; 



10. With diluted nitric acid ; 



11. With diluted hydrochloric acid. In all of which it remained without 

 change of colour. 



12. What is more remarkable, immersion in pjrroligneous acid does not efface 

 it when once thoroughly dry ; and it seems to become more fixed in the paper by 

 exposure to solar light and to the air. 



13. Pencilling common writing ink with liquid chloride of antimony imme- 

 diately discharges it ; but the same substance produces no effect on the new ink. 



14. Moderately diluted solutions of caustic alkalis, produce no effect on the 

 writing with this ink, though they injure the colom* of common inks immersed in 

 them ; but when the solutions are strong, they act on the texture of the paper, 

 and also soften the vehicle of the colouring matter, so that it may be partially 

 rubbed off ; but the softened texture of the paper becomes imbued with the car- 

 bon, producing a stain, which wiU shew the attempt at erasure. 



15. Slips of paper, written with the new ink, have been suffered to remain in 

 moderately strong alkaline solutions for seventy-two hours without any loss of 

 colour ; and when the paper is dried, the ink has again become as fii-m as before. 



1 6. It is not affected by the alkaline carbonates, nor by any of the neutral 

 salts hitherto applied to it ; nor am I aware of any chemical agent capable of 

 more effectually removing it from paper, than the substances already mentioned. 



It may be used with an iron pen, provided that pen be washed immediately 

 afterwards, for iron is not readily acted on by ascetic acid. 



It is not applicable as our ink for writing on parchment, because it may be 

 washed off that material hke every other ink, nor can it be employed for marking 

 linen. It is, in fact, only offered as a writing ink, to be used on paper, — weU 

 suited for the drawing out of bills, deeds, or wiEs ; or wherever it is important to 

 prevent the alteration of sums of money, or of signatures, as well as for handing 

 down to posterity public records, in a less perishable material than common ink. 



