Таинственный остров

           Therewasnowantoflime,onlytreatmentbylimewouldgivecalcareoussoap,insoluble,andconsequentlyuseless,whiletreatmentbysodawouldfurnish,onthecontrary,asolublesoap,whichcouldbeputtodomesticuse.Now,apracticalman,likeCyrusHarding,wouldrathertrytoobtainsoda.Wasthisdifficult?No;formarineplantsaboundedontheshore,glass-wort,ficoides,andallthosefucaceaewhichformwrack.Alargequantityoftheseplantswascollected,firstdried,thenburntinholesintheopenair.Thecombustionoftheseplantswaskeptupforseveraldays,andtheresultwasacompactgraymass,whichhasbeenlongknownunderthenameof"naturalsoda."

           Thisobtained,theengineertreatedthefatwithsoda,whichgavebothasolublesoapandthatneutralsubstance,glycerine.

           Butthiswasnotall.CyrusHardingstillneeded,inviewofhisfuturepreparation,anothersubstance,nitrateofpotash,whichisbetterknownunderthenameofsaltniter,orofsaltpeter.

           CyrusHardingcouldhavemanufacturedthissubstancebytreatingthecarbonateofpotash,whichwouldbeeasilyextractedfromthecindersofthevegetables,byazoticacid.Butthisacidwaswanting,andhewouldhavebeeninsomedifficulty,ifnaturehadnothappilyfurnishedthesaltpeter,withoutgivingthemanyothertroublethanthatofpickingitup.HerbertfoundaveinofitatthefootofMountFranklin,andtheyhadnothingtodobutpurifythissalt.

           Thesedifferentworkslastedaweek.