Sentence:  Now , driving the horse and sulky borrowed from Mynheer Schuyler , he felt as if every bone was topped by burning oil and that every muscle <WSD>was</WSD> ready to dissolve into jelly and leave his big body helpless and unable to move . 
Meaning of the word marked with <WSD> tags:  have the quality of being; (copula, used with an adjective or a predicate noun)