And have you not, in such a case, tried the word once or twice on the edge of the blotting-paper, or a spare scrap of paper, to see if it looked right? 
Haven't you tried the word once or twice to see what it looks like and still get it wrong?
mnli hypothesis: Haven't you tried the word once or twice to see what it looks like and still get it wrong? premise: And have you not, in such a case, tried the word once or twice on the edge of the blotting-paper, or a spare scrap of paper, to see if it looked right? 