[12。]Ricardo,op。cit。,p。421。\"Thequantityofmoneythatcanbeemployedinacountrymustdependonitsvalue:ifgoldalonewereemployedforthecirculationofcommodities,aquantitywouldberequired,onefifteenthonlyofwhatwouldbenecessary,ifsilverweremadeuseofforthesamepurpose。\"SeealsoRicardo,ProposalsforanEconomicalandSecureCurrency,London,1816,p。8,wherehewrites:\"Thequantityofmetalforwhichpapermoneyisthesubstitute,ifpapermoneybepartlyorwhollyused,mustdependonthreethings:first,onitsvalue;——secondly,ontheamountorvalueofthepaymentstobemade;——and,thirdly,onthedegreeofeconomypractisedineffectingthosepayments。\"
[13。]Ricardo,PrinciplesofPoliticalEconomy,pp。432,433
[14。]DavidRicardo,ReplytoMr。Bosanquet\'sPracticalObservations,p。49。\"Thatcommoditieswouldriseorfallinprice,inproportiontotheincreaseordiminutionofmoney,Iassumeasafactwhichisincontrovertible。\"
[15。]Ricardo,TheHighPriceofBullion。\"Moneywouldhavethesamevalueinallcountries\"（p。4）。RicardohasqualifiedthispropositioninhisPrinciplesofPoliticalEconomy,butnotsoastobeofanyimportanceinthiscontext。
[16。]Ricardo,op。cit。,pp。11,12。