Sentence:  The air vibrated at a white-hot temperature, the stones seemed to be trembling silently, ready to flow, and in the distance, at a curve of the road, the files of men, guns and horses seemed detached from the earth, and trembled like a mass of jelly in their onward progress, and it seemed to me that they were not living people that I saw before me, but an army of <WSD>incorporate</WSD> shadows. 
Meaning of the word marked with <WSD> tags:  Not consisting of matter; not having a material body; incorporeal; spiritual.