‘the silver-copper alloy containing about 71 to 72 per cent. of 
«“ silver (theoretically 71°89 per cent.) ; this silver-copper alloy 
“when melted and cast into a bar is homogeneous throughout. 
even when the bar is allowed to cool rapidly.” 
This is a most valuable piece of information and is of the 
greatest interest in the study of Pathan billon, It accounts in 
large measure for the very unsatisfactory results attained by 
tests in the past and forces us to reconsider decisions reachec 
by Thomas and apparently accepted without demur by his 
successors 
The expressed opinion of Thomas that billon coins had 
their value determined by sight and touch involves too large a 
the same weight and bearing identical legends should have 
been intended to pass current at different values. The appear- 
ance of the newly struck billon does not seem to have been 
taken into account. Appearances at the present day are most 
deceptive. A coin may seem to be pure copper, but after 
treatment by fire or by acid at the hands of the sonar the same 
coin will seemingly consist mainly of silver. Almost any billon 
can be cleaned so as to present a silvery appearance, and 
we have to think of the coins as they must have looked six 
hundred or more years ago, and not in their present guise as 
they appear after centuries of burial and exposure to chemical 
action. 
On this point the Master of H.M. Mint adds the following 
comment :— 
“The question of the composition and the methods of 
“identification of ancient coins to which you refer as dealt 
‘with by Edward Thomas is one which is quite outside the 
« work of the Mint. The suggestion that coins of the same 
‘< size and design had widely different values which were deter- 
‘mined by the public according to the appearance and touch 
“appears absurd from the modern point of view, since it is 
‘‘ alwavs considered of the first importance in designing and 
“ manufacturing coins to arrange that different denominations 
‘ shall be as distinctive as possible from each other, as regards 
“size and design, and different shapes are sometimes adopted 
“to give further distinctiveness.’ 
This was as true five hundred years ago as it is now. The 
various types obviously had different values, for otherwise all 
coins might have been of the same size and design. One has 
only to examine the great variety of the coinage in the days of 
Firoz, and others, such as Tughlaq II in particular, to feel 
assured that the suggestion put forward by Thomas is alto- 
gether untenable 
Practically all the information we possess as to the frac- 
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