Or, rather, to be more exact, Racksole could discern the legs of a man on that half of the table which was visible to him.

Involuntarily he shuddered, as the conviction forced itself upon him that Rocco had some unconscious human being helpless on that cold marble surface.

The legs never moved.

Therefore, the hapless creature was either asleep or under the influence of an anaesthetic--or (horrible thought!) dead.
Racksole wanted to call out, to stop by some means or other the dreadful midnight activity which was proceeding before his astonished eyes; but fortunately he restrained himself.
On the washstand he could see certain strangely-shaped utensils and instruments which Rocco used from time to time.

The work seemed to Racksole to continue for interminable hours, and then at last Rocco ceased, gave a sign of satisfaction, whistled several bars from 'Cavalleria Rusticana', and came into the bath-room, where he took off his coat, and very quietly washed his hands.