Sisame de Laponie in the Hand of Glory -- What Is It?

dead man's hand hand of glory magic
In the Petit Albert, the recipe for the Hand of Glory is as follows:

ON THE HAND OF GLORY, WHICH IS USED BY TREACHEROUS THIEVES, IN ORDER TO ENTER HOMES BY NIGHT WITHOUT HINDRANCE. I confess that I have never tested the secret of the Hand of Glory; but I have three times assisted in the convicting of certain miscreants who confessed under torture to have used the Hand of Glory in the thefts they had committed; and when during the interrogation they were asked what it was, how it was acquired, and what it was used for, they responded, firstly, that the purpose of the Hand of Glory was to entrance and make immobile those to whom it is shown, after which they become unable to stir, such as if they were dead; secondly, that it was the hand of a hanged man; thirdly, that it must be prepared in the following manner: One takes the right or left hand of a hanged man who has been left to the dogs; one wraps it in a piece of a funeral shroud, in which one presses it well so as to squeeze out the bit of blood which remains in it; then one places it in an earthenware container with some green vitriol, saltpeter, salt, and long pepper, all well pulverized. One leaves this resting in the pot for a fortnight, then having removed it one exposes it to the intense sun of the dog days of summer, until such point as it has become quite dry; and if the sunlight is not adequate, one places it in an oven fueled with ferns and vervain; then one composes a special candle with the fat of a hanged man, virgin wax and sisame de laponie, and it is set into the Hand of Glory like it is a candle holder, so that it grips the burning candle; and in all the places where one goes with this wretched device, so are people rendered immobile; and when after this they were asked if it did not have some remedy for the neutralizing of its trick, they said that the Hand of Glory became useless and that thieves could not make use of it if one rubbed the threshold of the door of the house, or of any other place through which they might enter, with an unguent composed from the gall of a black cat, fat of a white hen and the blood of an owl, and it was required that this confection should be made in the dog days of summer.

The question that has boggled minds for ages is what on earth Sisame de Laponie could be. Without it, one is unable to produce the charm.

The most obvious way to translate the phrase is "Sesame of Lapland" but, because Lapland does not possess a suitable climate for the growing of the plant sesamum indicum, it can be assumed the object in question is not a literal sesame. It may be another type of oily seed. There are those who argue that the phrase refers to manure and should be read as "sisame de la ponie" (pony's sesame, i.e. turds) but I would say that this is unlikely since pony -- despite ultimately having been derived from French poulain ("foal") -- was not a word in use in the French language at the time of the Albert's composition (Modern French poney is a loan-word from English.) If one is to argue for a non-standard reading of the word laponie, I myself would argue that it is derived from the Old French lape, meaning a burr, or sometimes the plant burdock in particular, whereby it could be read as something like "sesame of burr-like nature." (lape + diminutive suffix -on : yielding lapon "little burr" or "burr-like" with suffix -ie used to distinguish action or nature.) Another possibility is the word is a corruption, just like the Hand of Glory itself (Fr: Main de gloire) is a corruption from the word mandragore -- literally "mandrake" but really a word used to indicate many kinds of magical objects. 

It could also simply be a trick, either by the book's author or by one of the thieves that supposedly had used the Hand of Glory, to prevent anyone from actually being able to perform the spell, by listing a non-existent ingredient.