[November, 
674 Safety Cheques. 
Thus, once upon a time, all the world was inventing new 
methods of obtaining red colouring-matters from aniline oil. 
Another time all the world was no less busy devising new 
forms of roller skates. More recently all the world is up to 
its dazzled eyes in eledfric appliances, seeking to produce 
lights, whether “ incandescent” or “arc,” cheaper and more 
manageable than anything which has gone before. Hence, 
it appears that there is a class of inventors who seem always 
ready to turn their minds to any subject which attracts 
public attention. Among such less sensational, but still very 
important, subjects, we may mention methods of preventing 
a very dangerous fraud of the day, — the alteration of cheques 
after they have been filled in and signed by the drawer. 
This problem appears to have been solved in the most 
satisfactory manner (“Journal of Science,” 1881, p. 104) 
by Mr. A. Anthony Nesbit, F.C.S. His cheques have been 
pronounced by chemists profoundly versed in the properties 
of colouring-matters to be absolutely incapable of fraudulent 
alteration. So that on this score no improvement is needed 
or is even possible. But, of course, if any future inventor 
can give us equal security at a less cost for materials and 
labour, and with less trouble, he may claim the superiority. 
Has this been done, or is it likely to be done ? The Nesbit 
process requires no specially prepared paper ; any ordinary 
quality used for cheques will suffice. No complicated 
engraving is needed : the cheque is merely tinted with one 
of the colours, which are changed in different ways respec- 
tively by acids and by alkalies, and is then printed, a part of 
the design with an acid and another part with an alkaline 
ink. Simplicity, despatch, and economy in materials and 
labour can scarcely be carried further. 
One of the two attempts which have since been made to 
supersede the Nesbit cheque is not proof against alteration, 
as we have seen experimentally proved. A third process 
has been devised and patented by Mr. Nowlan,and is chiefly 
remarkable for its great complexity. As far as we under- 
stand the specification and claim — the latter not remarkable 
for clearness — Mr. Nowlan’s cheque is to consist of two or 
more layers of paper, as thin and transparent as possible. 
These leaves are printed with certain colouring-matters, 
some of them alterable and others permanent, and are then 
cemented together with their printed sides innermost. The 
designs, lines, letters, &c., will then have to be read through 
the uppermost paper, upon which, of course, the drawer’s 
signature and the sum will be written. 
We have never seen any experiments performed upon a 
