Then put it very fairly into a basinful of fresh water, and forthwith took it out, to see whether it were written with stone-alum.

But after all experiments, when he perceived that he could find out nothing, he called the messenger and asked him, Good fellow, the lady that sent thee hither, did she not give thee a staff to bring with thee?
thinking that it had been according to the conceit whereof Aulus Gellius maketh mention.

And the messenger answered him, No, sir.

Then Panurge would have caused his head to be shaven, to see whether the lady had written upon his bald pate, with the hard lye whereof soap is made, that which she meant; but, perceiving that his hair was very long, he forbore, considering that it could not have grown to so great a length in so short a time.
Then he said to Pantagruel, Master, by the virtue of G--, I cannot tell what to do nor say in it.

For, to know whether there be anything written upon this or no, I have made use of a good part of that which Master Francisco di Nianto, the Tuscan, sets down, who hath written the manner of reading letters that do not appear; that which Zoroastes published, Peri grammaton acriton; and Calphurnius Bassus, De literis illegibilibus.