Sentence:  Now , driving the horse and sulky borrowed from Mynheer Schuyler , he felt as if every bone was topped by burning <WSD>oil</WSD> and that every muscle was ready to dissolve into jelly and leave his big body helpless and unable to move . 
Meaning of the word marked with <WSD> tags:  a slippery or viscous liquid or liquefiable substance not miscible with water