see if it was written with the juice of white
onions.

Then he rubbed one part of it with oil of nuts, to see if it were not
written with the lee of a fig-tree, and another part of it with the milk of
a woman giving suck to her eldest daughter, to see if it was written with
the blood of red toads or green earth-frogs. Afterwards he rubbed one
corner with the ashes of a swallow's nest, to see if it were not written
with the dew that is found within the herb alcakengy, called the
winter-cherry. He rubbed, after that, one end with ear-wax, to see if it
were not written with the gall of a raven. Then did he dip it into vinegar,
to try if it was not written with the juice of the garden spurge. After
that he greased it with the fat of a bat or flittermouse, to see if it was
not written with the sperm of a whale, which some call ambergris. 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. But I
can see nothing, nor do I believe that there is anything else in it than
the ring. Let us, therefore, look upon it. Which when they had done, they
found this in Hebrew written within, Lamach saba(ch)thani; whereupon they
called Epistemon, and asked him what that meant. To which he answered that
they were Hebrew words, signifying, Wherefore hast thou forsaken me? Upon
that Panurge